Complete the revert on the wake lock on call tracker

On fallback from Gsm to LTE, the wakelock needs to be released on the underlying connection.
This should have gone in the previous CL.

Bug: 159462297
Test: atest FrameworksTelephonyTests
Test: Made phone call using Gsm/Cmda
Test: Monitored wakelocks with gsm while on call
Change-Id: I6fffd302fadba170b1461647c7094a732d17eed1