Merge "Treat R8 warnings as failures for system_server" am: 1f440e7a62 am: df2014cba1 am: 62fadfafd0

Original change: https://android-review.googlesource.com/c/platform/frameworks/base/+/2209838

Change-Id: I0b4efd58a380853842ec33fb2b7eb33c280155d8
Signed-off-by: Automerger Merge Worker <[email protected]>