Merge "DSDA: Support "Add call" from 2nd sub" into udc-dev am: 374b1ebd87 am: 3fa05ed9ae

Original change: https://googleplex-android-review.googlesource.com/c/platform/packages/services/Telecomm/+/21535964

Change-Id: Iadcf0843e6156b018f8450e92f5f8be63fd5eb6e
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>