a711ed8330
Add AccessibilityPreferenceController, which wraps all a11y settings since they are share common infrastructure for enabling, current value, and availability. We add an overlay for OEMs to declare their bundled a11y services. This is the only list of services that will be possible to enabled via Settings slices. Accessibility Slices are built by getting a list of valid services, and indexing the service names as a key in the Slices DB. When they are built at runtime, they use the generic A11yPrefController to get the status and enable/disable the service. Bug: 67997836 Bug: 67997672 Test: robotests Change-Id: I66f905bf1c55eecb937945c4675c12bcbc96d698