Add back Java resources to apk without Java code.

With commit 33360dd56925276e4526f5f52c26423e2bb1a670 we moved Java
resource packaging forward to creation of the jar file. But the Java
resource packaging will be skipped if a module has no Java code at all.
(The build system does support building an apk without Java code.)
In this change we add back the Java resources directly to the built apk
when the apk has no Java code.

Bug: 19947218
Change-Id: I0e1a65a9cbe656974f8ef3923b2f15e9efa5feb9
diff --git a/core/package_internal.mk b/core/package_internal.mk
index 134445b..4dbb1ac 100644
--- a/core/package_internal.mk
+++ b/core/package_internal.mk
@@ -423,7 +423,10 @@
 ifneq ($(jni_shared_libraries),)
 	$(add-jni-shared-libs-to-package)
 endif
-ifneq ($(full_classes_jar),)
+ifeq ($(full_classes_jar),)
+# We don't build jar, need to add the Java resources here.
+	$(if $(PRIVATE_EXTRA_JAR_ARGS),$(call add-java-resources-to,$@))
+else
 	$(add-dex-to-package)
 endif
 ifdef LOCAL_JACK_ENABLED