fix(rn,dialogs,auth) fix not showing authentication dialogs

1) Fix not being able to show multiple dialogs at once in iOS
2) Fix cancelling the login dialog when XMPP auth is enabled without
   guest support

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

@@ -6,7 +6,9 @@ import type { Dispatch } from 'redux';
 import { ConfirmDialog } from '../../../base/dialog';
 import { translate } from '../../../base/i18n';
 import { connect } from '../../../base/redux';
-import { openLoginDialog, cancelWaitForOwner } from '../../actions.native';
+import { cancelWaitForOwner } from '../../actions.native';
+
+import LoginDialog from './LoginDialog';
 
 /**
  * The type of the React {@code Component} props of {@link WaitForOwnerDialog}.
@@ -40,9 +42,14 @@ class WaitForOwnerDialog extends Component<Props> {
     constructor(props) {
         super(props);
 
+        this.state = {
+            showLoginDialog: false
+        };
+
         // Bind event handlers so they are only bound once per instance.
         this._onCancel = this._onCancel.bind(this);
         this._onLogin = this._onLogin.bind(this);
+        this._onLoginDialogCancel = this._onLoginDialogCancel.bind(this);
     }
 
     /**
@@ -58,7 +65,12 @@ class WaitForOwnerDialog extends Component<Props> {
                 confirmLabel = 'dialog.IamHost'
                 descriptionKey = 'dialog.WaitForHostMsg'
                 onCancel = { this._onCancel }
-                onSubmit = { this._onLogin } />
+                onSubmit = { this._onLogin }>
+                <LoginDialog
+                    // eslint-disable-next-line react/jsx-handler-names
+                    _onCancel = { this._onLoginDialogCancel }
+                    visible = { this.state.showLoginDialog } />
+            </ConfirmDialog>
         );
     }
 
@@ -83,7 +95,17 @@ class WaitForOwnerDialog extends Component<Props> {
      * @returns {void}
      */
     _onLogin() {
-        this.props.dispatch(openLoginDialog());
+        this.setState({ showLoginDialog: true });
+    }
+
+    /**
+     * Called when the nested login dialog is cancelled.
+     *
+     * @private
+     * @returns {void}
+     */
+    _onLoginDialogCancel() {
+        this.setState({ showLoginDialog: false });
     }
 }