Fix bot IDs for WebRTC trybots.
Fix bot IDs for WebRTC trybots.

The bot IDs for Android bots are a bit tricky. 
It turns out the Debug bot's ID matched the configuration that
runs the check_licenses step, which fails for WebRTC.
See src/build/android/buildbot/bb_run_bot.py in Chrome for details.

The Release bot ID also ended up running zip_build, which is pointless for us.

Changing the android_bot_id to use the main-clobber config instead
will make it only run the compile step, which is all we want for
our trybots.

TEST=ran a successful local build with the Android debug trybot ('android')
TBR=phoglund@chromium.org

Review URL: https://codereview.chromium.org/104853004

git-svn-id: 239fca9b83025a0b6f823aeeca02ba5be3d9fd76@241567 0039d316-1c4b-4281-b951-d872f2087c98

eunchong/build,eunchong/build,eunchong/build,eunchong/build