Merge "Add method to get all valid prefixes in PrefixDelegation class." into main am: f1feca062f am: 8dd0644d34 am: 9e27e8fecd

Original change: https://android-review.googlesource.com/c/platform/packages/modules/NetworkStack/+/2786161

Change-Id: I0adcc085036c3a9d6c53dca0161439ead1b7e38b
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>