Use -Werror in cts/.../Anroid.mk

* Suppress existing warnings.

Bug: 66996870
Test: build with WITH_TIDY=1
Change-Id: Ic599c9e11ea4f991b7e60930c891a6d736623b39
diff --git a/tests/cts/net/jni/Android.mk b/tests/cts/net/jni/Android.mk
index 887e95e..727a44d 100644
--- a/tests/cts/net/jni/Android.mk
+++ b/tests/cts/net/jni/Android.mk
@@ -28,7 +28,7 @@
 LOCAL_SHARED_LIBRARIES := libnativehelper_compat_libc++ liblog
 LOCAL_CXX_STL := libc++_static
 
-LOCAL_CFLAGS := -Wno-unused-parameter
+LOCAL_CFLAGS := -Wall -Werror -Wno-unused-parameter
 
 include $(BUILD_SHARED_LIBRARY)
 
@@ -37,6 +37,7 @@
 # Don't include this package in any configuration by default.
 LOCAL_MODULE_TAGS := optional
 LOCAL_SRC_FILES := NativeMultinetworkJni.c
+LOCAL_CFLAGS := -Wall -Werror -Wno-format
 LOCAL_C_INCLUDES := $(JNI_H_INCLUDE)
 LOCAL_SHARED_LIBRARIES := libandroid libnativehelper_compat_libc++ liblog
 LOCAL_CXX_STL := libc++_static