LinkProperties: use ordered comparison for P-CSCFs - only on U+ am: 15756bc0b1

Original change: https://googleplex-android-review.googlesource.com/c/platform/packages/modules/Connectivity/+/23367413

Change-Id: I5f4e81155c1b0107371b623db978b370f109587f
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>