Use -Werror in external/libvterm am: 3210a80411 am: 4687070036
am: bd0994e30e

Change-Id: I8f35d1849673859e2e954b53b56f5efb23599474
diff --git a/Android.bp b/Android.bp
index b09fd43..33d3b75 100644
--- a/Android.bp
+++ b/Android.bp
@@ -16,8 +16,11 @@
 
     cflags: [
         "-std=c99",
+        "-Wall",
+        "-Werror",
         "-Wno-missing-field-initializers",
         "-Wno-sign-compare",
+        "-Wno-unused-function",
         "-Wno-unused-parameter",
     ],
 }