OVERVIEW : 

Recently, I came across an issue where the reflections used for collapsing status bar were not working from Android 12. When I tried to find alternative solutions, I got one using Accessibility Service in Android.

Reflections used for collapsing status bar :

// Prior to API 17, the method to call is 'collapse()'
// API 17 onwards, the method to call is `collapsePanels()`

Object sbservice = context.getSystemService("statusbar");
try {
   Class<?> statusbarManager = Class.forName("android.app.StatusBarManager");
   Method collapseStatusBar = null;
   if (Build.VERSION.SDK_INT <= 16) {
       collapseStatusBar = statusbarManager.getMethod("collapse");
   } else {
       collapseStatusBar = statusbarManager.getMethod("collapsePanels");
   }
   collapseStatusBar.setAccessible(true);
   collapseStatusBar.invoke(sbservice);

} catch (Exception e) {
   e.printStackTrace();
}

statusBarManager.getMethod(“collapsePanels”); is not working from API 31 since it is hidden.

Alternative solution for preventing Status Bar Expansion from API 31 & above using Accessibility Service :

We can use AccessibilityService.GLOBAL_ACTION_DISMISS_NOTIFICATION_SHADE to prevent Status Bar Expansion when pulled down.

/*** Dismisses the notification panel when pulled down ***/
public boolean dismissNotificationShade() {
   try {
   if(Build.VERSION.SDK_INT >= 31) {
       return performGlobalAction(GLOBAL_ACTION_DISMISS_NOTIFICATION_SHADE);
   }
}
catch (Exception e){
   e.printStackTrace();
}
return false;
}

AccessibilityService class must be extended in order to use the above method.

Note : This method should be called continuously in the background thread. If the status/notification bar is pulled down, then this method will dismiss the bar and return true, otherwise false will be returned. 

Hope it resolves your issue.
Thanks for reading,
Cheers!