Generate warning settings for Android framework

Bug: b/66996870

Android wants to build with warnings as errors. Keep the external/skia
warnings in sync with other Skia builds by pulling them from the json
generated by GN.

Fix a couple small errors that show up in the framework build.

Uploaded in response to AOSP's
https://android-review.googlesource.com/#/c/platform/external/skia/+/498211/

Change-Id: I4d791d43a9b00f9d6b79ecf16839716f241cba99
Reviewed-on: https://skia-review.googlesource.com/55703
Commit-Queue: Leon Scroggins <scroggo@google.com>
Reviewed-by: Mike Klein <mtklein@chromium.org>
3 files changed