[automerger skipped] DO NOT MERGE: Delete TestNetworkStackLib and reduce NetworkStack lib visibility. am: 0c12622623 -s ours

am skip reason: subject contains skip directive

Original change: https://googleplex-android-review.googlesource.com/c/platform/packages/modules/NetworkStack/+/13733930

MUST ONLY BE SUBMITTED BY AUTOMERGER

Change-Id: Ib2801a63b0828dadea9827b304a96d00c428c605