Merge changes from topics "delegate_regi_new_state_losing_pdn", "ims_rcs_api_improvement_delegate_regi_state" am: 5fd9a457ce am: b1e1f7b730

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

Change-Id: Ia4e74e6f342476997e25719867b1d4ac5faae2c0