Fix Regex for unit test

Author: dellis1972

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

@@ -673,7 +673,7 @@ public void BuildAotApplication (string supportedAbis, bool enableLLVM, bool exp
 					// LLVM passes a direct path to libc.so, and we need to use the libc.so
 					// which corresponds to the *minimum* SDK version specified in AndroidManifest.xml
 					// Since we overrode minSdkVersion=10, that means we should use libc.so from android-9.
-					var rightLibc   = new Regex (@"^\s*\[AOT\].*cross-.*--llvm.*,ld-flags=.*android-9.arch-.*.usr.lib.libc\.so", RegexOptions.Multiline);
+					var rightLibc   = new Regex (@"\s*\[aot-compiler stdout].*android-9.arch-.*.usr.lib.libc\.so", RegexOptions.Multiline);
 					var m           = rightLibc.Match (string.Join ("\n",b.LastBuildOutput));
 					Assert.IsTrue (m.Success, "AOT+LLVM should use libc.so from minSdkVersion!");
 				}