[aab] Make base module targets

This prepares for synchronized proguarding and allows us to configure
the base modules differently than the Chrome APKs.

+ Stop making an APK if building a module.

Bug: 862696
Change-Id: I28b245888241e3519454c8957fcf0e460925f459
Reviewed-on: https://chromium-review.googlesource.com/1138870
Commit-Queue: Tibor Goldschwendt <tiborg@chromium.org>
Reviewed-by: David Turner <digit@chromium.org>
Reviewed-by: agrieve <agrieve@chromium.org>
Cr-Commit-Position: refs/heads/master@{#577012}
4 files changed