Moved practically all of the prerefactoring functionality to the new design.

Renamed LayoutTestsRunner activity to TestsListActivity. It will be responsible for restrating the Executer after the crash. Now it only starts
it.
Renamed LayoutTestsRunnerThread to TestsListPreloaderThread. It only preloads tests now.
LayoutTest class is no longer needed, its functionality is in LayoutTestsExecuter.
Most of the functionality from LayoutTestsRunnerThread is now in ManagerService.

Change-Id: I08924d949ceb9f8816888bc8e795256d0542fa99