fix(rn,bottom-sheet) fixed surface color

Also fix properly showing the remote menu.

react/features/base/dialog/components/native/BottomSheet.js

                     <SafeAreaView
                         style = { [
                             styles.sheetItemContainer,
-                            _styles.sheet,
+                            renderHeader
+                                ? _styles.sheetHeader
+                                : _styles.sheet,
                             style,
                             {
                                 maxHeight: _height - 100

react/features/base/dialog/components/native/styles.js

 
 import { StyleSheet } from 'react-native';
 
+import BaseTheme from '../../../../base/ui/components/BaseTheme.native';
 import { ColorSchemeRegistry, schemeColor } from '../../../color-scheme';
 import { BoxModel, ColorPalette } from '../../../styles';
 import { PREFERRED_DIALOG_SIZE } from '../../constants';
      * Bottom sheet's base style.
      */
     sheet: {
-        backgroundColor: ColorPalette.black,
+        backgroundColor: BaseTheme.palette.ui02,
         borderTopLeftRadius: 16,
         borderTopRightRadius: 16
+    },
+
+    /**
+     * Bottom sheet's base style with header.
+     */
+    sheetHeader: {
+        backgroundColor: BaseTheme.palette.ui02
     }
 });
 

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

                     participant
                 }));
             }
-
-            return null;
+        } else {
+            dispatch(openDialog(RemoteVideoMenu, {
+                participant
+            }));
         }
-
-        dispatch(openDialog(RemoteVideoMenu, {
-            participant
-        }));
     }, [ participant, dispatch ]);
 
     return (