Fix excluding resource directories

Using a glob as a path failed the existence check.  Append the
glob after converting the path to a string.

Test: TestExcludeResources in java_test.go
Change-Id: Ic1fd40aa283f3b0d59c1c589dbeec411583eddf1

java/resources.go

@@ -47,7 +47,8 @@ func ResourceDirsToJarArgs(ctx android.ModuleContext,
 	var excludes []string
 
 	for _, exclude := range excludeDirs {
-		excludes = append(excludes, android.PathForModuleSrc(ctx, exclude, "**/*").String())
+		excludes = append(excludes,
+			filepath.Join(android.PathForModuleSrc(ctx, exclude).String(), "**/*"))
 	}
 
 	excludes = append(excludes, resourceExcludes...)