health: Update README.md for SELinux rule example am: d4ebad8aef am: a68e416fee am: c8b2bc6339 am: b38d6e929f

Original change: https://android-review.googlesource.com/c/platform/hardware/interfaces/+/1894882

Change-Id: Id69a8900a62136911720473d5903a6744138081d