* [dev] Don't use await for on stdout and stdin; pass local engine argument

1) Don't use await for on stdout followd by await for on stderr.
   This can cause nothing to happen. E.g. if one didn't do something
   like `flutter pub upgrade` dev/automated_tests and the version in the
   old one was pre-nnbd (but flutter itself use lots of nnbd stuff) lots
   of errors would be emitted, but because we basically only listen to
   stdout nothing will happen (deadlock once stderr buffer runs out).
   Note that it still awaits the exit-code below.
2) Pass --local-engine (if given) so there won't be any crashes because
   of that.

This reverts commit d3a2db22.

This reverts commit d4c77f31.

This reverts commit 273630c0.

* Create icons golden test

* Update icons_test.dart

* Update icons_test.dart

* Update icons_test.dart

* change test name

* Add ability to load material icon font for golden tests

* formatting

* Skip test for browser

* Add end of file newline

Adds an example to the docs for ActionListener.

This reverts commit 4901744e, which was a minor breaking change that I missed.  Will try to open the PR again following the breaking change process.

43ee609f0 [camera_platform_interface] Add platform interface methods for locking capture orientation. (flutter/plugins#3389) (#73469)

This reverts commit 655cd1e2.

dac4b6f3c [camera_platform_interface] Add platform interface methods for setting auto focus. (flutter/plugins#3369) (#73436)

* Minor doc, style, and perf updates to Navigator/Routes

These are minor fixes I ended up making while working on a larger
project that never went anywhere.

- Used a ColoredBox instead of a DecoratedBox for ModalBarrier
  (probably a trivial memory/perf win).

- A bunch of Navigator documentation fixes around when things rebuild.

- Mark routes dirty when the Navigator has a dependency change. I
  cannot find a way to test this because as far as I can tell it makes
  no actual difference to when things rebuild because whenever the
  Navigator rebuilds the Overlay rebuilds and whenever that happens
  every OverlayEntry rebuilds, but in theory that's not guaranteed so
  this is sort of a correctness fix. It may even be a perf loss. We do
  something similar in didUpdateWidget already. I could be convinced
  to maybe remove these...

- Make ModalRoute.filter public like everything else.

- Made ModalRoute update its barrier when it gets an update, in case
  e.g. the modal barrier depends on inherited widgets via the
  navigator context. Again, not sure of any way to detect this, it
  might actually be moot, but it seems to be the technically correct
  solution?

- Minor style fixes.

All in all I couldn't figure out a way to test any of this (I wrote
multiple large tests but it turns out they all already pass on master
and are effectively redundant with existing tests).

* Remove extraneous blank line

This reverts commit 28db5a0f.