roomservice: switch to omni's roomservice and crDroid'fy

Change-Id: I22253621f9b5a6577df80c94471adaa1d2a8068d
Cleaner and shorter CRDROID_TARGET_PACKAGE description and some little fixes in envsetup.sh

Change-Id: Iadfc3184818f5cfb53da1726f9f9bfd781839a26