Merge "Fix threading issue for mDefaultNetworkRequests" into main am: a5a549bfd8

Original change: https://android-review.googlesource.com/c/platform/packages/modules/Connectivity/+/3251251

Change-Id: Id94ff94086cebf10361254f05f68c76bf6bbcf62
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>