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

* Suppress existing warnings.

Bug: 66996870
Test: build with WITH_TIDY=1
Change-Id: Ic599c9e11ea4f991b7e60930c891a6d736623b39
diff --git a/hostsidetests/abioverride/app/jni/Android.mk b/hostsidetests/abioverride/app/jni/Android.mk
index c500100..d806a2c 100644
--- a/hostsidetests/abioverride/app/jni/Android.mk
+++ b/hostsidetests/abioverride/app/jni/Android.mk
@@ -26,7 +26,7 @@
 LOCAL_C_INCLUDES := $(JNI_H_INCLUDE)
 
 # Ignore unused parameters.
-LOCAL_CFLAGS += -Wno-unused-parameter
+LOCAL_CFLAGS += -Wall -Werror -Wno-unused-parameter
 
 LOCAL_SHARED_LIBRARIES := libnativehelper_compat_libc++ liblog libdl
 LOCAL_CXX_STL := none