Apply PRODUCT_ENFORCE_RRO_TARGETS to dependencies.

With this change, users don't need to figure out which libraries
actually hold the resources to be overlaid when targetting apps with a
core lib dependency (e.g. Settings, SystemUI).

Fixes: 169898727
Test: app_test.go
Change-Id: I3c3b9dc0a377b1828db1199858a73d080a173205

java/java_test.go

@@ -102,6 +102,10 @@ func testContext() *android.TestContext {
 
 	dexpreopt.RegisterToolModulesForTest(ctx)
 
+	ctx.PostDepsMutators(func(ctx android.RegisterMutatorsContext) {
+		ctx.TopDown("propagate_rro_enforcement", propagateRROEnforcementMutator).Parallel()
+	})
+
 	return ctx
 }