Merge "Improve removing PROPERTY_IS_DOWNGRADED_CONFERENCE from connection" am: 1a5f580122 am: a4f1ffc59b am: 0992d6e1b5

Original change: https://android-review.googlesource.com/c/platform/packages/services/Telephony/+/2171284

Change-Id: I877e9c8c1892f6c56dc6a659fe15adf915553799
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>