Add more brightness config details to dumpsys

Allow client to add a description to a brightness
config and dump to dumpsys
Dump time and package name of system app that
set the last brightness config.

Bug: 71854421
Test: atest PersistentDataStoreTest
Test: manaual - check adb shell dumpsys display
Change-Id: I5ff0c0d3a4c5e30c9d4aa7eea850c7174ee20450