flutter/flutter#62143

[fuchsia] fix and re-enable SessionConnection unittests

This change waits until Scenic is initialized before beginning the test
logic. This should fix the issue where the test starts running before or
during Scenic startup.

* Prevent crash when restore is called after picture recording ends
* Addressed reviewer comments

This reverts commit 8825f917 because it breaks flutter_gallery__back_button_memory and a customer test.

* [web] Fix arc scaling when counter clockwise
* update golden write
* Removed unused var