Implement a11y UI for Accessibility timeout feature.

This UI control the Accessibility Timeout API in Settings App.
Add a user control to set timeout length to suit their need.

Bug: 119283926
Test: atest AccessibilityTimeoutControllerTest
Test: make RunSettingsRoboTests -j ROBOTEST_FILTER=CodeInspectionTest
Test: atest UniquePreferenceTest
Change-Id: Ic8f7337e6bd7739c1189382cc87d45465b64c6ed