Android: Update android studio docs for canary

Remove upgrading 2.2 to 2.3 since it has been stable for a while in
preparation for stabilization of 3.0.

BUG=620034

Change-Id: I249dba940edf4b3d54ac35d3e5b7d612917d18e7
Reviewed-on: https://chromium-review.googlesource.com/617320
Commit-Queue: Andrew Grieve <agrieve@chromium.org>
Reviewed-by: Andrew Grieve <agrieve@chromium.org>
Cr-Commit-Position: refs/heads/master@{#495170}
1 file changed