Reland: [CupertinoActionSheet] Add sliding tap gesture (#150219)

Relands flutter/flutter#149471. 

As explained in flutter/flutter#150147, the original PR was reverted in an attempt to fix the strange golden file failure that occurred in other PRs.

The following code is changed:
* The two tests that contain golden tests are changed so that, they used to slide from button 1 to button 2, now they slide from button 2 to button 1. This is to ensure the golden file record are updated.

Author: dkwingsmt