Merge changes from topics "delegate_regi_new_state_losing_pdn", "ims_rcs_api_improvement_delegate_regi_state" am: a570a8259b

Original change: https://android-review.googlesource.com/c/platform/packages/services/Telephony/+/1911014

Change-Id: I36b63ea0e1a5dd75c35c539aa54cb82dbdaed78e