Set mBound only when bind succeeds

Fixes an issue that TV input is disabled forever after package upgrade,
when it's upgraded while in use.  The root cause is as below:

- Package is killed while upgrade.
- Service disconnects, and tries to rebind for reconnecting, but bind fails
  because service is not available temporarily.  Still ServiceState.mBound is
  set to true.
- Should rebind next when callback is registered or new session is created,
  but doesn't because ServiceState is already marked bound.

Bug: 14981201
Change-Id: Ia5b0acb33f1247064213024438f114bc40238648