fix: set explicit color for search field to avoid theme override

react/features/invite/components/add-people-dialog/native/styles.js

         backgroundColor: 'rgb(240, 243, 247)',
         borderBottomRightRadius: 10,
         borderTopRightRadius: 10,
+        color: DARK_GREY,
         flex: 1,
         fontSize: 17,
         paddingVertical: 7