Revert "TelephonyManager: cache service handles"

Revert "Disable Telephony service handle caching while testing."

Revert submission 9592007-telephony-handle-caching

Reason for revert: Breaks tests
(com.android.cellbroadcastreceiver.unit.CellBroadcastConfigServiceTest,
com.android.bluetooth.hfp.HeadsetPhoneStateTest).

Reverted Changes:
If9bb6840c: TelephonyManager: cache service handles
I3b525c504: Disable Telephony service handle caching while tes...

Bug: 147656950
Bug: 147655973
Bug: 147658833
Bug: 147658836
Bug: 147658970
Bug: 140788621
Change-Id: Id4eb23c237c514c86af92a85c8637404eca1c357