Automated cherry pick of #3588 (#3596)

* MM-20201 Fixed asterisk on Nickname

Added optional prop to the Nickname field, which removes the asterisk

* MM-20201 Updated Position field also

Added optional prop to position field.

app/screens/edit_profile/edit_profile.js

@@ -470,6 +470,7 @@ export default class EditProfile extends PureComponent {
                 theme={theme}
                 value={nickname}
                 isLandscape={isLandscape}
+                optional={true}
             />
         );
     };
@@ -493,6 +494,7 @@ export default class EditProfile extends PureComponent {
                 theme={theme}
                 value={position}
                 isLandscape={isLandscape}
+                optional={true}
             />
         );
     };