[RN] Honor filmstrip visibility state

react/features/filmstrip/components/Filmstrip.native.js

  */
 function _mapStateToProps(state) {
     const participants = state['features/base/participants'];
+    const { visible } = state['features/filmstrip'];
 
     return {
         /**
          * @private
          * @type {boolean}
          */
-        _visible: participants.length > 1
+        _visible: visible && participants.length > 1
     };
 }