[Xamarin.Android.Build.Tasks] @(LibraryResourceDirectories)+R.java (#744)

Fixes: https://bugzilla.xamarin.com/show_bug.cgi?id=58721

The initial problem seems to stem from the fact that for the support
library components now directly include the resources. As a result
the `_GenerateJavaResourcesForComponent` target was not running. This
was because it was only running if
`$(_AdditonalAndroidResourceCachePaths)` was not empty. In this
scenario it was always empty.

As a result none of the files like `R.java` files were generated for
the support libraries. The means the final `.class` files did not
have references for the `R$drawable.foo` identifiers.

This results in a crash:

	Java.Lang.NoClassDefFoundError: Failed resolution of: Landroid/support/v7/appcompat/R$drawable;

Fix the problem by looking at `@(LibraryResourceDirectories)` to see
if we have any `AndroidManifest.xml` files. We should then process
these directories to ensure that the `R.java` files are created and
included compiled into the final applications.

Author: dellis1972

src/Xamarin.Android.Build.Tasks/Tests/Xamarin.Android.Build.Tests/AndroidUpdateResourcesTest.cs

@@ -1,4 +1,4 @@
-using System;
+using System;
 using Xamarin.ProjectTools;
 using NUnit.Framework;
 using System.Linq;
@@ -110,6 +110,29 @@ public void DesignTimeBuild ([Values(false, true)] bool isRelease)
 			}
 		}
 
+		[Test]
+		public void CheckEmbeddedSupportLibraryResources ()
+		{
+			var proj = new XamarinAndroidApplicationProject () {
+				IsRelease = true,
+				Packages = {
+					KnownPackages.SupportMediaCompat_25_4_0_1,
+					KnownPackages.SupportFragment_25_4_0_1,
+					KnownPackages.SupportCoreUtils_25_4_0_1,
+					KnownPackages.SupportCoreUI_25_4_0_1,
+					KnownPackages.SupportCompat_25_4_0_1,
+					KnownPackages.AndroidSupportV4_25_4_0_1,
+					KnownPackages.SupportV7AppCompat_25_4_0_1,
+				},
+				TargetFrameworkVersion = "v7.1",
+			};
+			using (var b = CreateApkBuilder ("temp/CheckEmbeddedSupportLibraryResources")) {
+				Assert.IsTrue (b.Build (proj), "First build should have succeeded.");
+				var Rdrawable = b.Output.GetIntermediaryPath (Path.Combine ("android", "bin", "classes", "android", "support", "v7", "appcompat", "R$drawable.class"));
+				Assert.IsTrue (File.Exists (Rdrawable), $"{Rdrawable} should exist");
+			}
+		}
+
 		[Test]
 		public void MoveResource ()
 		{

src/Xamarin.Android.Build.Tasks/Tests/Xamarin.ProjectTools/Android/KnownPackages.cs

@@ -40,6 +40,15 @@ public static class KnownPackages
 					MetadataValues = "HintPath=..\\packages\\Xamarin.Android.Support.v4.23.1.1.0\\lib\\MonoAndroid403\\Xamarin.Android.Support.v4.dll" }
 			}
 		};
+		public static Package AndroidSupportV4_25_4_0_1 = new Package () {
+			Id = "Xamarin.Android.Support.v4",
+			Version = "25.4.0.1",
+			TargetFramework = "MonoAndroid70",
+			References = {
+				new BuildItem.Reference ("Xamarin.Android.Support.v4") {
+					MetadataValues = "HintPath=..\\packages\\Xamarin.Android.Support.v4.25.4.0.1\\lib\\MonoAndroid70\\Xamarin.Android.Support.v4.dll" }
+			}
+		};
 		public static Package AndroidSupportV4Beta = new Package () {
 			Id = "Xamarin.Android.Support.v4",
 			Version = "21.0.0.0-beta1",
@@ -139,6 +148,60 @@ public static class KnownPackages
 					MetadataValues = "HintPath=..\\packages\\Xamarin.Android.Support.v7.AppCompat.23.1.1.0\\lib\\MonoAndroid403\\Xamarin.Android.Support.v7.AppCompat.dll" }
 			}
 		};
+		public static Package SupportV7AppCompat_25_4_0_1 = new Package {
+			Id = "Xamarin.Android.Support.v7.AppCompat",
+			Version = "25.4.0.1",
+			TargetFramework = "MonoAndroid70",
+			References = {
+				new BuildItem.Reference ("Xamarin.Android.Support.v7.AppCompat") {
+					MetadataValues = "HintPath=..\\packages\\Xamarin.Android.Support.v7.AppCompat.25.4.0.1\\lib\\MonoAndroid70\\Xamarin.Android.Support.v7.AppCompat.dll" }
+			}
+		};
+		public static Package SupportCompat_25_4_0_1 = new Package {
+			Id = "Xamarin.Android.Support.Compat",
+			Version = "25.4.0.1",
+			TargetFramework = "MonoAndroid70",
+			References = {
+				new BuildItem.Reference ("Xamarin.Android.Support.Compat") {
+					MetadataValues = "HintPath=..\\packages\\Xamarin.Android.Support.Compat.25.4.0.1\\lib\\MonoAndroid70\\Xamarin.Android.Support.Compat.dll" }
+			}
+		};
+		public static Package SupportCoreUI_25_4_0_1 = new Package {
+			Id = "Xamarin.Android.Support.Core.UI",
+			Version = "25.4.0.1",
+			TargetFramework = "MonoAndroid70",
+			References = {
+				new BuildItem.Reference ("Xamarin.Android.Support.Core.UI") {
+					MetadataValues = "HintPath=..\\packages\\Xamarin.Android.Support.Core.UI.25.4.0.1\\lib\\MonoAndroid70\\Xamarin.Android.Support.Core.UI.dll" }
+			}
+		};
+		public static Package SupportCoreUtils_25_4_0_1 = new Package {
+			Id = "Xamarin.Android.Support.Core.Utils",
+			Version = "25.4.0.1",
+			TargetFramework = "MonoAndroid70",
+			References = {
+				new BuildItem.Reference ("Xamarin.Android.Support.Core.Utils") {
+					MetadataValues = "HintPath=..\\packages\\Xamarin.Android.Support.Core.Utils.25.4.0.1\\lib\\MonoAndroid70\\Xamarin.Android.Support.Core.Utils.dll" }
+			}
+		};
+		public static Package SupportFragment_25_4_0_1 = new Package {
+			Id = "Xamarin.Android.Support.Fragment",
+			Version = "25.4.0.1",
+			TargetFramework = "MonoAndroid70",
+			References = {
+				new BuildItem.Reference ("Xamarin.Android.Support.Fragment") {
+					MetadataValues = "HintPath=..\\packages\\Xamarin.Android.Support.Fragment.25.4.0.1\\lib\\MonoAndroid70\\Xamarin.Android.Support.Fragment.dll" }
+			}
+		};
+		public static Package SupportMediaCompat_25_4_0_1 = new Package {
+			Id = "Xamarin.Android.Support.Media.Compat",
+			Version = "25.4.0.1",
+			TargetFramework = "MonoAndroid70",
+			References = {
+				new BuildItem.Reference ("Xamarin.Android.Support.Media.Compat") {
+					MetadataValues = "HintPath=..\\packages\\Xamarin.Android.Support.Media.Compat.25.4.0.1\\lib\\MonoAndroid70\\Xamarin.Android.Support.Media.Compat.dll" }
+			}
+		};
 		public static Package SupportV7MediaRouter_21_0_3_0 = new Package {
 			Id = "Xamarin.Android.Support.v7.MediaRouter",
 			Version = "21.0.3.0",

src/Xamarin.Android.Build.Tasks/Xamarin.Android.Common.targets

@@ -1211,8 +1211,7 @@ because xbuild doesn't support framework reference assemblies.
 </PropertyGroup>
 
 <Target Name="_GenerateJavaDesignerForComponent"
-  Condition="'@(_AdditonalAndroidResourceCachePaths)' != ''"
-  Inputs="@(_AdditonalAndroidResourceCacheFiles)"
+  Inputs="@(_AdditonalAndroidResourceCacheFiles);@(_LibraryResourceDirectoryStamps)"
   Outputs="$(_AndroidComponentResgenFlagFile)"
   DependsOnTargets="$(_GenerateJavaDesignerForComponentDependsOnTargets)">
 
@@ -1221,7 +1220,7 @@ because xbuild doesn't support framework reference assemblies.
    ImportsDirectory="$(_LibraryProjectImportsDirectoryName)"
    OutputImportDirectory="$(_AndroidLibrayProjectIntermediatePath)"
    UseShortFileNames="$(UseShortFileNames)"
-   ManifestFiles="@(_AdditonalAndroidResourceCachePaths->'%(Identity)\AndroidManifest.xml')"
+   ManifestFiles="@(_AdditonalAndroidResourceCachePaths->'%(Identity)\AndroidManifest.xml');@(LibraryResourceDirectories->'%(Identity)\..\AndroidManifest.xml')"
    ApplicationName="$(_AndroidPackage)"
    JavaPlatformJarPath="$(JavaPlatformJarPath)"
    NonConstantId="true"