Update DozeScreenState and DozeBrightnessChange logs

* No functional changes to the user; only updates debug logging.
* Move the logs to the class that extends DreamService for
readability.
* Log before and after the request to update screen state and
brightness changes.
* Brightness change logs are now written from the background thread
instead of the original (main) thread to be more accurate of
when the change actually occurs.
* Bunch of formatting fixes

Test: view logs are still existent (DozeLog in dumpsys of sysui)
Test: atest DozeSuspendScreenStatePreventingAdapterTest
Flag: EXEMPT bugfix
Bug: 358578071
Change-Id: I423f22c2714f0c8ccf988a4147eb76fef7f3dfdf