Merge changes I744d2ba5,Ieae1a882,Id7604ce3,If99a05bd,I27190251, ...

* changes:
  Floss: Integrate powerd Suspend/Resume API
  Floss: Define D-Bus projection for Suspend API in btmanagerd
  Floss: Refactors ClientDBusProxy to be reusable
  Floss: Implement no-op Suspend/Resume API
  Floss: Add ServiceWatcher D-Bus utility
  Floss: Add protobuf build to btmanagerd
  Floss: Refactor btmanagerd's RPCProxy