Add Night Light Suggestion and tests

Night Light settings suggestion will only show when the user
has not previously interacted with Night Light.

Bug: 37207263
Test: make ROBOTEST_FILTER=\
"(SettingsSuggestionsTest|SuggestionFeatureProviderImplTest)"\
RunSettingsRoboTests
Change-Id: I432d5fef19f5e4a52503da136b044598cb82164a