Fix unnecessary adb server restarting

Update common lib where the following change is applied: In case the user had not specified image (--avd option is not used) when using emulate command, there's no need to retry restarting adb server in case there's at least one running emulator. We can use it directly.
Merge pull request #504 from Icenium/vladimirov/fix-adb-server-restarts

Fix unnecessary adb server restarting