Improve message for unable to emulate

Update common lib where the following changes are applied:
Improve message when android emulator cannot start. When the virtual device is using Android L and its RAM <= 512MB the emulator cannot start the application. Moved sleeping at the end of each retry when checking for emulator boot in order to prevent unnecessary 10 secs wait.
Merge pull request #506 from Icenium/vladimirov/fix-android-L

Improve message for unable to emulate