Use -Werror in packages/inputmethods/LatinIME/native/jni

Bug: 66996870
Test: build with WITH_TIDY=1
Change-Id: I6b91302908e147077bb4fd0a8718c39357337133
diff --git a/native/jni/HostUnitTests.mk b/native/jni/HostUnitTests.mk
index baf1cac..94cd764 100644
--- a/native/jni/HostUnitTests.mk
+++ b/native/jni/HostUnitTests.mk
@@ -42,6 +42,7 @@
 LATIN_IME_TEST_SRC_DIR := tests
 LOCAL_ADDRESS_SANITIZER := true
 LOCAL_CFLAGS += -Wno-unused-parameter -Wno-unused-function
+LOCAL_CFLAGS += -Wall -Werror
 LOCAL_CXX_STL := libc++
 LOCAL_C_INCLUDES += $(LOCAL_PATH)/$(LATIN_IME_SRC_DIR)
 LOCAL_MODULE := liblatinime_host_unittests