feat(navigation) two actions screen header buttons ui updates

react/features/etherpad/components/native/SharedDocument.js

@@ -72,8 +72,7 @@ class SharedDocument extends PureComponent<Props> {
             headerLeft: () => (
                 <HeaderNavigationButton
                     onPress = { goBack }
-                    src = { IconArrowBack }
-                    style = { styles.headerArrowBack } />
+                    src = { IconArrowBack } />
             )
         });
     }

react/features/etherpad/components/native/styles.js

@@ -5,11 +5,6 @@ import { ColorPalette } from '../../../base/styles';
 export const INDICATOR_COLOR = ColorPalette.lightGrey;
 
 export default {
-
-    headerArrowBack: {
-        marginLeft: 12
-    },
-
     indicatorWrapper: {
         alignItems: 'center',
         backgroundColor: ColorPalette.white,