HIG for export share sheet

Summary:
Following https://developer.apple.com/design/human-interface-guidelines/macos/buttons/push-buttons/,
the primary button should be highlighted and the affirmative action be to the right.

Clicked a few times on the wrong one myself.

Reviewed By: priteshrnandgaonkar

Differential Revision: D17762516

fbshipit-source-id: 6be35cfde26ca10142c2c98df30672c0f739c17e

src/chrome/SelectPluginSheet.tsx

@@ -165,18 +165,18 @@ export default class SelectPluginSheet extends Component<Props, State> {
         <Padder paddingTop={8} paddingBottom={2}>
           <FlexRow>
             <Spacer />
+            <Button compact padded onClick={onHide}>
+              Close
+            </Button>
             <Button
               compact
               padded
-              type={'success'}
+              type="primary"
               onClick={() => {
                 this.onSubmit(this.state.plugins);
               }}>
               Submit
             </Button>
-            <Button compact padded onClick={onHide}>
-              Close
-            </Button>
           </FlexRow>
         </Padder>
       </Container>