Some optimizations

Author: dellis1972

src/Xamarin.Android.Build.Tasks/MSBuild/Xamarin/Android/Xamarin.Android.Assets.targets

@@ -34,6 +34,7 @@ Copyright (C) 2011-2012 Xamarin. All rights reserved.
 <PropertyGroup>
 	<BeforeBuildAndroidAssetPacks>
 		UpdateAndroidAssets
+		;_CalculateAssetsWithAssetPackMetaData
 		;_CalculateAssetPacks
 		;$(BeforeBuildAndroidAssetPacks)
 		;_CreateAssetPackManifests
@@ -74,22 +75,23 @@ Copyright (C) 2011-2012 Xamarin. All rights reserved.
 	</ItemGroup>
 </Target>
 
-<Target Name="_CheckForAssetPackInLibraryProject" Condition=" '$(AndroidApplication)' != 'true' ">
+<Target Name="_CalculateAssetsWithAssetPackMetaData">
 	<ItemGroup>
 		<_AssetsWithAssetPackMetaData Include="@(AndroidAsset)" Condition=" '%(AndroidAsset.AssetPack)' != '' " />
 	</ItemGroup>
 	<AndroidError 
 		Code="XA0138"
 		ResourceName="XA0138"
-		Condition=" '@(_AssetsWithAssetPackMetaData->Count())' != '0' "
+		Condition=" '$(AndroidApplication)' != 'true' And '@(_AssetsWithAssetPackMetaData->Count())' != '0' "
 	/>
 </Target>
 
 <Target Name="_CalculateAssetPacks"
+		DependsOnTargets="_CalculateAssetsWithAssetPackMetaData"
 		Condition=" ('$(AndroidPackageFormat)' == 'aab' And '$(AndroidApplication)' == 'true') "
 	>
 	<!-- Enumerate the assetpacks directory and build a pack per top level directory -->
-	<GetAssetPacks Assets="@(AndroidAsset)" IntermediateDir="$(MonoAndroidAssetPacksDirIntermediate)">
+	<GetAssetPacks Assets="@(_AssetsWithAssetPackMetaData)" IntermediateDir="$(MonoAndroidAssetPacksDirIntermediate)">
 		<Output ItemName="_AndroidAsset" TaskParameter="AssetPacks" />
 	</GetAssetPacks>
 	<ItemGroup>

src/Xamarin.Android.Build.Tasks/Microsoft.Android.Sdk/targets/Microsoft.Android.Sdk.BuildOrder.targets

@@ -92,7 +92,7 @@ properties that determine build ordering.
       _AddAndroidDefines;
       _CheckForContent;
       _CheckForObsoleteFrameworkAssemblies;
-      _CheckForAssetPackInLibraryProject;
+      _CalculateAssetsWithAssetPackMetaData;
       _RemoveLegacyDesigner;
       _ValidateAndroidPackageProperties;
       AddLibraryJarsToBind;