Merge "Reset mNetDataPrefixes when Thread goes down." into main am: e71571d178 am: 7ca99651d2

Original change: https://android-review.googlesource.com/c/platform/packages/modules/Connectivity/+/3094998

Change-Id: Ie57ca3858d5555009b1370e8a1a741af5bfb50e5
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>