[Android] Set AccessibilityNodeInfo.stateDescription so TalkBack stops reading "checked. on." on switches

Description

On Android, a view with accessibilityRole="switch" and accessibilityState={{ checked: true }} is read by TalkBack as "checked. on.". TalkBack takes "on" from the Switch class name and "checked" from isChecked. It suppresses the generic word only when stateDescription is set (API 30+).

ReactAccessibilityDelegate.kt on main never calls setStateDescription: for STATE_CHECKED it sets only isCheckable and isChecked. No JS prop reaches stateDescription, so apps can't fix this without native code.

A related request, #34736 ("Custom State Descriptions"), was closed by the stale bot in 2023 without a PR.

Steps to reproduce

1. Render <Pressable accessibilityRole="switch" accessibilityState={{ checked: true }} accessibilityLabel="Notifications" />.
2. Turn on TalkBack and focus the element.
3. Hear "checked. on." in the announcement.

Expected

The state is read once ("on"), not twice.

Suggested fix

In ReactAccessibilityDelegate, when accessibilityState.checked is set, also call ViewCompat.setStateDescription (or AccessibilityNodeInfoCompat.setStateDescription). For role switch it would be "on"/"off", and for role checkbox "checked"/"not checked", using Android's own localized strings. Alternatively, expose accessibilityValue.text as the stateDescription.

Versions

• React Native 0.85.3 (Expo SDK 56). Also confirmed on main up to v0.88.0-rc.1 by reading the source.
• TalkBack 17.

Start in ReactAccessibilityDelegate.kt, at the STATE_CHECKED handling, and trace how accessibilityRole and accessibilityState reach the Android node. Compare the suggested ViewCompat or AccessibilityNodeInfoCompat stateDescription behavior for switch and checkbox roles, then verify the announcement no longer repeats the state while existing accessibility behavior remains intact.