clearCallingIdentity for every CallControl API in TSW

A test failure uncovered a bug with the TransactionalServiceWrapper class.  The InCallController was throwing a SecurityException when
getting user information from the call. The InCallController should have been running under Telecoms Identity. Turns out this was due to the TSW class not clearing the calling identity.

Bug: 330184947
Test: modifying TransactionalApisTest#testSendCallEvent
Change-Id: I2191a92c66f8d62f7d00500eeb1ba9fc8bc1629d