Merge "[Thread] save time in InternetAccessTest by only joining the network once" into main am: cfa0475787

Original change: https://android-review.googlesource.com/c/platform/packages/modules/Connectivity/+/3335540

Change-Id: Ibfb9d278b1858d8cc8cc733dc253487f4db7374d
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>