Refactor OWNERS in platform/prebuilts/build-tools am: 0a2bd86863 am: f0d1a5f110 am: 7b6f1c117f

Original change: https://android-review.googlesource.com/c/platform/prebuilts/build-tools/+/1455795

Change-Id: I4af751552e0d08e532cad3b1a80a092fc40038b0