Add check for java reserved works in AndroidResource items

src/Xamarin.Android.Build.Tasks/Properties/Resources.resx

@@ -139,6 +139,9 @@ This error is likely caused by an issue with the AndroidManifest.xml file or an
   <data name="APT0004" xml:space="preserve">
     <value>Invalid file name: It must start with A-z or a-z or an underscore.</value>
   </data>
+  <data name="APT0005" xml:space="preserve">
+    <value>Invalid file name: Filenames cannot use Java reserved words.</value>
+  </data>
   <data name="XA0000_API_for_TargetFrameworkVersion" xml:space="preserve">
     <value>Could not determine API level for $(TargetFrameworkVersion) of '{0}'.</value>
     <comment>The following are literal names and should not be translated: $(TargetFrameworkVersion)

src/Xamarin.Android.Build.Tasks/Tasks/CheckForInvalidResourceFileNames.cs

@@ -22,6 +22,8 @@ public class CheckForInvalidResourceFileNames : AndroidTask {
 		Regex fileNameCheck = new Regex ("[^a-zA-Z0-9_.]+", RegexOptions.Compiled);
 		Regex fileNameWithHyphenCheck = new Regex ("[^a-zA-Z0-9_.-]+", RegexOptions.Compiled);
 
+		Regex fileNameJavaReservedWordCheck = new Regex("^\\b(abstract|continue|for|new|switch|assert|default|goto|package|synchronized|boolean|do|if|private|this|break|double|implements|protected|throw|byte|else|import|public|throws|case|enum|instanceof|return|transient|catch|extends|int|short|try|char|final|interface|static|void|class|finally|long|strict|fp|volatile|const|float|native|super|while)\\b$", RegexOptions.Compiled);
+
 		public override bool RunTask ()
 		{
 			foreach (var resource in Resources) {
@@ -45,6 +47,10 @@ public override bool RunTask ()
 					if (match.Success) {
 						Log.LogCodedError ("APT0003", resource.ItemSpec, 0, Properties.Resources.APT0003, fileNameCheck);
 					}
+					match = fileNameJavaReservedWordCheck.Match (Path.GetFileNameWithoutExtension (fileName));
+					if (match.Success) {
+						Log.LogCodedError ("APT0005", resource.ItemSpec, 0, Properties.Resources.APT0005, fileNameCheck);
+					}
 				}
 			}
 			return !Log.HasLoggedErrors;

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

@@ -50,6 +50,21 @@ public class CheckForInvalidResourceFileNamesTests : BaseTest {
 				false,
 				2,
 			},
+			new object[] {
+				"import.xml",
+				false,
+				1,
+			},
+			new object[] {
+				"class.png",
+				false,
+				1,
+			},
+			new object[] {
+				"class1.png",
+				true,
+				0,
+			},
 		};
 #pragma warning restore 414
 		[Test]