Use cargo2android.py with a patch file.

* Reduce manual editing the .bp file after a version upgrade.
* Use --ignore-cargo-errors to suppress output of the cargo/rustc
  error messages in Android.bp, so the patch will produce a clean result.
* Add post_update.sh to copy android/* and remove upstream OWNERS.

Bug: 172093078
Test: make and regenerate .bp
Change-Id: Ie8ba0e7fb48018f18678554d3ab08ccd62610792
3 files changed