Print actual list of failing tests on Android layout test steps

This changes the Android bots to mimic the behavior of the non-Android bots
and to print the actual list of failing/flaky/unexpected passing tests
as part of the step text.

R=ilevy@chromium.org
BUG=293920

Review URL: https://codereview.chromium.org/26330004

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@227850 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 227850