Roll engine to cb3376c (flutter#16841)

This contains the following commit:

flutter/engine@cb3376c Support different encodings in Image.toByteData() (flutter#16635)

Fix capitalization in README.md (flutter#16788)

Do exponential backoff for all exceptions in VMService::defaultOpenCh…

…annel. (flutter#16785)

We were trying to only catch WebSocketException, but in fact
SocketException can be thrown as well.

Fix a bug in the AnimatedChildSwitcher, add builders. (flutter#16250)

This fixes a rendering problem in the AnimatedChildSwitcher where it would add a new "previous" child each time it rebuilt, and if you did it fast enough, all of them would disappear from the page.

It also expands the API for AnimatedChildSwitcher to allow you to specify your own transition and/or layout builder for the transition.

Fixes flutter#16226

Update dependencies (flutter#16442)

[fuchsia] Fixes for Fuchsia hot reload (flutter#16317)

Adding onTapDown and onTapCancel to InkWell (flutter#16190)

 Let CupertinoTabScaffold's tab be programmatically selectable (flutt…

…er#16040)

* Let CupertinoTabScaffold's tab be programmatically selectable

* Re-use the tab bar's index instead

* review

Update logic for parsing sdk version number (flutter#15918)

* add logic to parse 11.3 sim runtime major version

* add null aware and bump group number

* add comment describing version

Roll engine to 9af82c5 (flutter#16088)

Includes:
* libtxt: move to the next run if the current run ends before the start of the line block (flutter/engine#4891)
* Rolled Dart SDK to e3051175192c83fafa3636c0f16d804734bb285a (flutter/engine#4877)