Implement DPI variants in android_app_import.

Bug: 128610294
Test: app_test.go
Change-Id: Ie3e558bfdb40de6b0b9df95d3b373d08a4084d7b
diff --git a/java/java_test.go b/java/java_test.go
index 5335d78..4b850ef 100644
--- a/java/java_test.go
+++ b/java/java_test.go
@@ -164,7 +164,9 @@
 		"prebuilts/sdk/tools/core-lambda-stubs.jar":   nil,
 		"prebuilts/sdk/Android.bp":                    []byte(`prebuilt_apis { name: "sdk", api_dirs: ["14", "28", "current"],}`),
 
-		"prebuilts/apk/app.apk": nil,
+		"prebuilts/apk/app.apk":        nil,
+		"prebuilts/apk/app_xhdpi.apk":  nil,
+		"prebuilts/apk/app_xxhdpi.apk": nil,
 
 		// For framework-res, which is an implicit dependency for framework
 		"AndroidManifest.xml":                        nil,