Move display tests to DisplayServiceTests module

Migrate tests.
Add dependencies to build files.
Add permissions to manifest.

Additionally, LogicalDisplayTest#testDisplayInputFlags() has been marked
as @Ignore, with a TODO, and will be fixed in followup bug: 288880734

Also used the opportunity to correctly format the indentation in &
change some other minor aesthetic & style guide corrections in:
AmbientBrightnessStatsTrackerTest
AmbientLuxTest
BrightnessMappingStrategyTest
BrightnessThrottlerTest
BrightnessTrackerTest
ColorDisplayServiceTest
HighBrightnessModeControllerTest
PersistentDataStoreTest

Bug: 286043820
Test: atest DisplayServiceTests
Change-Id: Ib5235bcd184d35a7efec922606d4566b839d4a74