Update tools/ OWNERS to valid owners and remove noparent rule to allow for...

Update tools/ OWNERS to valid owners and remove noparent rule to allow for parent owners in cases where needed. am: c9bc3941

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/16373401

Change-Id: I4a7dfffa04611310363928ff547eb4677c1c3290