Add the possibility to use a fixed port for adb daemon

This allows to start an adb daemon on system startup and keep it running after the job ends.
A running adb is needed if emulators and real devices are used on the same machine.

Change-Id: Id9a742b440cf0daa1595ed89fd392a6433940290
Keep the emulator really in workspace

If the emulator should stay in workspace, it is expected that also the avd config is loaded from current workspace.
This patch enables this behaviour.

Change-Id: Ib325f20578c5262d54ab53383c353ad81c889fa7