Merge "Add unit tests checking MTU of interfaces are set." am: edbf34a182 am: 320207fcf1 am: 2321fd3918

Original change: https://android-review.googlesource.com/c/platform/packages/modules/Connectivity/+/2335546

Change-Id: Ib1d929c1ac8213857fa8ecf070f9aa94b582acf0
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>