Android: Rename chrome->libchrome and document various apk targets

The rename will help to call out that multiple build targets exist on
Android.

Bug: 731186
Change-Id: I1dbe2ffe932b25ab8739f53c2cd05c2ee3d8b2b6
Reviewed-on: https://chromium-review.googlesource.com/682770
Commit-Queue: Andrew Grieve <agrieve@chromium.org>
Reviewed-by: Tommy Nyquist <nyquist@chromium.org>
Cr-Commit-Position: refs/heads/master@{#504257}
2 files changed