Merge "Add methods to get the minimal preferred/valid lifetime of delegated prefix." into main am: fd9f5586ee

Original change: https://android-review.googlesource.com/c/platform/packages/modules/NetworkStack/+/2691416

Change-Id: Ided37f6c1ee286e25ae720b27d29da3a18c3b492
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>