Adding UI for sticky keys indicator

Adds:
- coordinator that collects ViewModel and decides if dialog should be shown or hidden + its unit test
- view implementation in Compose: StickyKeysIndicator
- fake implementation for StickyKeysRepository
- fake of KeyboardRespository to Kosmos for easy reuse

Starting of coordinator + its flag will be added in the follow-up change.

Bug: 313855932
Test: StickyKeysIndicatorCoordinatorTest
Flag: N/A - code is not reachable yet
Change-Id: I704346f1b81d1a90ab2ab3141752f2c58e20ac38