Migrated notification module from Java to Kotlin (commons-app#5955)

* Rename .java to .kt

* Migration of notification module from Java to Kotlin

Author: Saifuddin53

app/src/main/java/fr/free/nrw/commons/contributions/ContributionsFragment.java

@@ -289,7 +289,7 @@ public void onCreateOptionsMenu(@NonNull final Menu menu,
             });
         }
         notification.setOnClickListener(view -> {
-            NotificationActivity.startYourself(getContext(), "unread");
+            NotificationActivity.Companion.startYourself(getContext(), "unread");
         });
     }
 

app/src/main/java/fr/free/nrw/commons/contributions/MainActivity.java

@@ -414,7 +414,7 @@ public boolean onOptionsItemSelected(MenuItem item) {
                 return true;
             case R.id.notifications:
                 // Starts notification activity on click to notification icon
-                NotificationActivity.startYourself(this, "unread");
+                NotificationActivity.Companion.startYourself(this, "unread");
                 return true;
             default:
                 return super.onOptionsItemSelected(item);