Use -Werror in hardware/interfaces/automotive/vehicle/2.0

Bug: 66996870
Test: build with WITH_TIDY=1
Change-Id: I439352bb0f876bac10393c08c9bdaa665709b147
diff --git a/automotive/vehicle/2.0/default/impl/vhal_v2_0/proto/Android.bp b/automotive/vehicle/2.0/default/impl/vhal_v2_0/proto/Android.bp
index ec35200..6754843 100644
--- a/automotive/vehicle/2.0/default/impl/vhal_v2_0/proto/Android.bp
+++ b/automotive/vehicle/2.0/default/impl/vhal_v2_0/proto/Android.bp
@@ -23,5 +23,9 @@
     strip: {
         keep_symbols: true,
     },
+    cflags: [
+        "-Wall",
+        "-Werror",
+    ],
     srcs: ["VehicleHalProto.proto"]
 }