Fix Android.mk.

- You don't need to explicitly specify protobuf library; The library
  name has been changed and the build system automatically adds it.
- You can't have a file target $(LOCAL_BUILT_MODULE) depend on phony target
  launcher_protoutil_lib.
- "include $(call all-makefiles-under,$(LOCAL_PATH))" must be on the
  last line.

(cherry picked from commit 3d74c663)

Change-Id: I27d967a57d6a9373da50821af32191614a3c8bc7