Add android_app_import.

This is an initial version that handles the most basic cases.

Bug: 128610294
Test: app_test.go + prebuilt webview.apk
Change-Id: Ic525559aad5612987e50aa75b326b77b23acb716
diff --git a/java/java_test.go b/java/java_test.go
index 3fab43d..5335d78 100644
--- a/java/java_test.go
+++ b/java/java_test.go
@@ -63,6 +63,7 @@
 	ctx := android.NewTestArchContext()
 	ctx.RegisterModuleType("android_app", android.ModuleFactoryAdaptor(AndroidAppFactory))
 	ctx.RegisterModuleType("android_app_certificate", android.ModuleFactoryAdaptor(AndroidAppCertificateFactory))
+	ctx.RegisterModuleType("android_app_import", android.ModuleFactoryAdaptor(AndroidAppImportFactory))
 	ctx.RegisterModuleType("android_library", android.ModuleFactoryAdaptor(AndroidLibraryFactory))
 	ctx.RegisterModuleType("android_test", android.ModuleFactoryAdaptor(AndroidTestFactory))
 	ctx.RegisterModuleType("android_test_helper_app", android.ModuleFactoryAdaptor(AndroidTestHelperAppFactory))
@@ -163,6 +164,8 @@
 		"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,
+
 		// For framework-res, which is an implicit dependency for framework
 		"AndroidManifest.xml":                        nil,
 		"build/make/target/product/security/testkey": nil,