AOD: Show charging status on AOD1

- Change PowerManager to not turn on display when on AOD
- Add charging icon to AOD1
- Add transient charging indication when plugged in

Bug: 30876804
Bug: 35850304
Test: runtest systemui; enable AOD, plug in phone, verify charging indicator shows, verify charging text shows and goes away after a few seconds
Change-Id: Icb80843a12c56c7e2abeca78115a366b4d508d4f