Add CarrierConfig to remove hold during Ims Calls

Adds a Carrier Config key to specify whether an IMS call supports
holding. If not, the CAPABILITY_HOLD and CAPABILITY_SUPPORT_HOLD are
not added to the Connection.

Bug: 30195356
Change-Id: I9b16b385a2b90118453d484be5af4f173b199ab1
1 file changed