Make sure vibration previews in Settings apply latest intensities

Update the Settings app to enforce fresh settings are applied to preview
vibrations triggered after the intensity is updated.

Add preview haptics to main switch, only when touch feedback is enabled,
and to the "apply ramping ringer" toggle for consistency with the rest
of the screen, using ringtone intensity for preview.

Bug: 219693646
Bug: 219695212
Bug: 157533521
Test: manual
Change-Id: I872a75d6b00dffae943b0f403185a39047909884

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

@@ -23,6 +23,8 @@ import android.content.Context;
 import android.database.ContentObserver;
 import android.net.Uri;
 import android.os.Handler;
+import android.os.VibrationAttributes;
+import android.os.Vibrator;
 import android.provider.Settings;
 
 import com.android.settings.R;
@@ -42,9 +44,11 @@ public class VibrationMainSwitchPreferenceController extends SettingsMainSwitchP
         implements LifecycleObserver, OnStart, OnStop {
 
     private final ContentObserver mSettingObserver;
+    private final Vibrator mVibrator;
 
     public VibrationMainSwitchPreferenceController(Context context, String preferenceKey) {
         super(context, preferenceKey);
+        mVibrator = context.getSystemService(Vibrator.class);
         mSettingObserver = new ContentObserver(new Handler(/* async= */ true)) {
             @Override
             public void onChange(boolean selfChange, Uri uri) {
@@ -79,9 +83,17 @@ public class VibrationMainSwitchPreferenceController extends SettingsMainSwitchP
 
     @Override
     public boolean setChecked(boolean isChecked) {
-        return Settings.System.putInt(mContext.getContentResolver(),
+        boolean success = Settings.System.putInt(mContext.getContentResolver(),
                 VibrationPreferenceConfig.MAIN_SWITCH_SETTING_KEY,
                 isChecked ? ON : OFF);
+
+        if (success && isChecked) {
+            // Play a haptic as preview for the main toggle only when touch feedback is enabled.
+            VibrationPreferenceConfig.playVibrationPreview(
+                    mVibrator, VibrationAttributes.USAGE_TOUCH);
+        }
+
+        return success;
     }
 
     @Override