Gives unvailable slice of Night Light a customized subtitle

When a slice depends on some setting and the setting is off,
it shows "depends on another setting".
Base on the new introduced attribute on ag/5843828 , assigns
customized subtitle for showing the unavailabe slice when the
Night Light is off.

Change-Id: I5c3530281fac4ef63caf2d3ac8e2be872d704bcb
Fixes: 118399193
Test: Manual