Add display specific brightness configurations

Add brightness configuration to display state, within the persistentDataStore. The original brightness configurations remain under the name "mGlobalBrightnessConfigurations".
Expose methods to get and set brightness configurations specific to each display. Indexed by uniqueId of the physical display. Where necessary, the primary physical display device of the logical display is used when identifying this.

Bug: 181767734
Test: atest PersistentDataStoreTest BrightnessConfigurationTest BrightnessTest

Change-Id: Idaed53e8f4abe548784781c4fb610dbada46ab19