open another app from ours?

This link : (https://forum.unity3d.com/threads/android-ios-launch-from-within-a-unity-app-another-unity-app.222709/#post-1486300) is kinda similar to what I am looking for, but since I wanted to open Gallery, I don't know what activity to call or what Intent, I mean I just wanted to know what should I write for opening gallery activity.

Take a look at this code :

 bool fail = false;
 string bundleId = com.google.appname; //target bundle id for gallery!?
 AndroidJavaClass up = new AndroidJavaClass("com.unity3d.player.UnityPlayer");
 AndroidJavaObject ca = up.GetStatic<AndroidJavaObject>("currentActivity");
 AndroidJavaObject package$$anonymous$$anager = ca.Call<AndroidJavaObject>("getPackage$$anonymous$$anager");
      
 AndroidJavaObject launchIntent = null;
 try
 {
     launchIntent = package$$anonymous$$anager.Call<AndroidJavaObject>("getLaunchIntentForPackage",bundleId);
 }
 catch (System.Exception e)
 {
     fail = true;
 }
  
 if (fail)
 { //open app in store
     Application.OpenURL("https://google.com");
 }
 else //I want to open Gallery App? But what activity?
     ca.Call("startActivity",launchIntent);
  
 up.Dispose();
 ca.Dispose();
 package$$anonymous$$anager.Dispose();
 launchIntent.Dispose();

Now, I want to open gallery activity in the else block, Any Idea how can I do that? Thanks for sharing!!

I found my native android gallery's bundle ID, so I replaced the code above with this:

 string bundleId = "com.android.gallery3d";

But it doesn't helps me either, it does not open anything!