Merge changes from topics "delegate_regi_new_state_losing_pdn",...

Merge changes from topics "delegate_regi_new_state_losing_pdn", "ims_rcs_api_improvement_delegate_regi_state" am: 5fd9a457 am: b1e1f7b7 am: cd1a6331

Original change: https://android-review.googlesource.com/c/platform/frameworks/base/+/1911013

Change-Id: I59b316cfaca93e3216437fee391051780901c8f6