[automerger skipped] Merge "Delete TestNetworkStackLib and reduce NetworkStack lib visibility." am: b775d9bc am: 49ead3b4 -s ours

am skip reason: skipped by user lorenzo

Original change: https://android-review.googlesource.com/c/platform/packages/modules/NetworkStack/+/1611755

MUST ONLY BE SUBMITTED BY AUTOMERGER

Change-Id: I891fc287151fb604aec7d9350ed1cd49e7af327d