Android: Using R8 instead of ProGuard for public targets

Bug: 908988
Change-Id: Iaaee8124c56945a8769e6d4ff2a0859ef39c1aea
Reviewed-on: https://chromium-review.googlesource.com/c/1355424
Reviewed-by: agrieve <agrieve@chromium.org>
Commit-Queue: Sam Maier <smaier@chromium.org>
Cr-Commit-Position: refs/heads/master@{#612439}
4 files changed