[Launcher] Don't rely on argv[0] when looking for the engine

Use System::getProgramDirectory() instead of argv[0] to find the
engine to run.

+ Removed 'tryCurrentPath' logic as it's not needed anymore

Bug: https://code.google.com/p/android/issues/detail?id=197084
(merge from emu-master-dev)

Change-Id: I570ed996cfefd9a986a0fbe3240ef3ea5da18bf7
1 file changed