Using more comprehensive flags for sticky keys feature

This feature depends on 2 flags and UI should not depend just on 1.

Bug: 313855932
Test: feature is enabled for 2 flags, not just 1
Flag: ACONFIG com.android.hardware.input.keyboard_a11y_sticky_keys_flag TRUNKFOOD
Change-Id: I171ca730aa0e568840c090954b141baec430bf59