Merge "DSDA: Support "Add call" from 2nd sub" into udc-dev am: 374b1ebd am: b87af455

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



Change-Id: I62408a4bccbfb4e04c6f8b1fc65481fe2693df9c
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>