Revert "misc: remove duplicated declarations"

This reverts commit 7e831117b6.

react/features/authentication/components/WaitForOwnerDialog.native.js

         );
     }
 
+    _onCancel: () => void;
+
     /**
      * Called when the cancel button is clicked.
      *
         this.props.dispatch(cancelWaitForOwner());
     }
 
+    _onLogin: () => void;
+
     /**
      * Called when the OK button is clicked.
      *