RTT initialization bugfixes

Properly dispose of old RTT data pipes
Add logging
Read the system setting to see if we should start the call with RTT
Deal with connection managers that possibly support RTT

Bug: 71873552
Test: manual
Change-Id: I12f67ca977bd97302c7e5a21a7374f085e5865ce
Merged-In: I12f67ca977bd97302c7e5a21a7374f085e5865ce