Remove duplicate strings.

"Yes" and "no" were redefined many times with no clear benefit, so this
consolidates them into one definition.

Bug: 243843096
Test: Build, install, and open the Settings app
Test: atest SettingsRoboTests
Change-Id: I5f84d09f223efd478461ded93aeac82bf7b128d8

src/com/android/settings/accessibility/AccessibilityUtil.java

@@ -130,8 +130,7 @@ public final class AccessibilityUtil {
     static CharSequence getSummary(Context context, String settingsSecureKey) {
         final boolean enabled = Settings.Secure.getInt(context.getContentResolver(),
                 settingsSecureKey, State.OFF) == State.ON;
-        final int resId = enabled ? R.string.accessibility_feature_state_on
-                : R.string.accessibility_feature_state_off;
+        final int resId = enabled ? R.string.on : R.string.off;
         return context.getResources().getText(resId);
     }