Grant 'w' rights to for-system subdirectory for root. am: d9025190fa am: ab80af8eb5 am: a5810680ea

Original change: https://android-review.googlesource.com/c/platform/packages/modules/Connectivity/+/1969499

Change-Id: Ibd0dad59f71d02a9730b36243263ee73d3fc38a5