* NNBD widget test migration

These androidx migration tests require downloading firebase, which is a large library with a number of dependencies - this causes frequent enough flakes.

AndroidX migration is ~2 years in the past, and while it would be nice to confirm this still works, ideally that would be done in a reduced manner.

* [flutter_tools] partial revert of start app change

- run_without_leak_tests: have been disabled for months
- build_benchmark: the tooling work here is mostly done and we're not tracking further improvements, free up more devicelab capacity
- system_debug_ios: does not work post iOS13
- mac_enable_twc: not adding more mac tests to devicelab
- hello_world_start_up: disabled

Any tests that we think will be valuable in the future can be resurrected from the git history.

Revert "[flutter_tools] If run fails to install the application on iOS, try uninstalling it and trying again. (#68078)" (#68118)

This reverts commit 61ba7dd2.

[flutter_tools] If run fails to install the application on iOS, try uninstalling it and trying again. (#68078)

[Material] Parent checkbox in DataTable should deselect all, if children checkboxes are disabled or selected  (#67938)

* modify: add prefix `Alignment.` for toString of Alignment

Do not allow attach in release mode, as there is not VM Service to connect to. Observed in crash reporting as thrown string which is changed to exception below.

--use-application-binary allows running with an already built APK. This can be useful for speeding up CI test cases, or in our case eventually supporting some sort of build server. Demonstrate that this works by updating the old gallery test to use it. Fixes #56604
Co-authored-by: Jenn Magder <magder@google.com>

* Fix docset generation.

* Remove checks to be able to test.

* More logging

* More logging

* More logging.

* more logging.

* More logging.

* Add flags to firebase command.

* Re-enable docset generation.

* Disable firebase step.

* Comment docset to speed up validations.

* Re-enable docset.

* Add back condition to prevent uploading docs from PRs.

* Migrate more Material framework tests to null safety.

Migrating some more widget tests to NNBD.

Remove "This is taking a long time" progress timeout and TimeoutConfiguration.

* Migrate more tests

* fix

Fake has been moved from mockito to test to facilitate NNBD, re-export this from flutter_test