Revert "Revert "Make build warnings be errors""

This reverts commit 984b4f2db2f5969afff6420739f6d785f4a14bf3.

Change-Id: I4d0f420a063c611afe5b5c9fa809e34799f66ea1
diff --git a/media/mediaserver/Android.mk b/media/mediaserver/Android.mk
index 2cec5d2..1738df8 100644
--- a/media/mediaserver/Android.mk
+++ b/media/mediaserver/Android.mk
@@ -5,6 +5,7 @@
 LOCAL_SRC_FILES := register.cpp
 LOCAL_MODULE := libregistermsext
 LOCAL_MODULE_TAGS := optional
+LOCAL_CFLAGS := -Werror -Wall
 include $(BUILD_STATIC_LIBRARY)
 endif
 
@@ -39,4 +40,6 @@
 
 LOCAL_INIT_RC := mediaserver.rc
 
+LOCAL_CFLAGS := -Werror -Wall
+
 include $(BUILD_EXECUTABLE)