Merge changes from topics "delegate_regi_new_state_losing_pdn", "ims_rcs_api_improvement_delegate_regi_state" am: a570a8259b am: d8d853ca17 am: 2e41ec38ff

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

Change-Id: I21d5d238d895249ec5499b3c433b19d62b5be88a