Frameworks/base: Wall Werror in native/android

Turn on -Wall -Werror in native/android.

Change-Id: I28bab9ebd2fe3f6935878816773a04531e26450f
diff --git a/native/android/Android.mk b/native/android/Android.mk
index cda38e0..b3a74a8 100644
--- a/native/android/Android.mk
+++ b/native/android/Android.mk
@@ -34,6 +34,8 @@
     frameworks/base/native/include \
     frameworks/base/core/jni/android
 
-LOCAL_MODULE:= libandroid
+LOCAL_MODULE := libandroid
+
+LOCAL_CFLAGS += -Wall -Werror -Wunused -Wunreachable-code
 
 include $(BUILD_SHARED_LIBRARY)