Merge "Set dialog background activity start mode on U+" am: 7b766a2ff6

Original change: https://android-review.googlesource.com/c/platform/packages/modules/Connectivity/+/2528741

Change-Id: I3c6ed300657dea28dd6d7ba89e1a1c48ca196a37
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>