Use -Werror in hardware/interfaces

* Use hidl_defaults, which has -Wall -Werror.

Bug: 66996870
Test: build with WITH_TIDY=1
Change-Id: Ifbca0e176a8e031acc27256eb46d23b89cdf1a0e
diff --git a/gnss/1.0/default/Android.bp b/gnss/1.0/default/Android.bp
index 007ed97..ca495e6 100644
--- a/gnss/1.0/default/Android.bp
+++ b/gnss/1.0/default/Android.bp
@@ -1,5 +1,6 @@
 cc_library_shared {
     name: "android.hardware.gnss@1.0-impl",
+    defaults: ["hidl_defaults"],
     vendor: true,
     relative_install_path: "hw",
     srcs: [
@@ -27,14 +28,13 @@
         "libhardware",
     ],
 
-    cflags: ["-Werror"],
-
 }
 
 cc_binary {
     relative_install_path: "hw",
     vendor: true,
     name: "android.hardware.gnss@1.0-service",
+    defaults: ["hidl_defaults"],
     init_rc: ["android.hardware.gnss@1.0-service.rc"],
     srcs: ["service.cpp"],