This reverts commit 8b6baae4.

Our current top crasher is an unclear error when ProcessManager fails to resolve an executable path. To fix this, we'd like to being adjusting the process resolution logic and adding more instrumentation to track failures. In order to begin the process, the ProcessManager has been folded back into the flutter tool

* opt out the flutter tool

* oops EOF

* fix import

* Update tool_backend.dart

* Update daemon_client.dart

* fix more

* [flutter_tools] simplication of application store logic

* maybe return null

* fix install tests

* Clean up imports

* revert windows test

* remove unused import

* Update project.pbxproj files to say Flutter rather than Chromium

Also, the templates now have an empty organization so that we don't cause people to give their apps a Flutter copyright.

* Update the copyright notice checker to require a standard notice on all files

* Update copyrights on Dart files. (This was a mechanical commit.)

* Fix weird license headers on Dart files that deviate from our conventions; relicense Shrine.

Some were already marked "The Flutter Authors", not clear why. Their
dates have been normalized. Some were missing the blank line after the
license. Some were randomly different in trivial ways for no apparent
reason (e.g. missing the trailing period).

* Clean up the copyrights in non-Dart files. (Manual edits.)

Also, make sure templates don't have copyrights.

* Fix some more ORGANIZATIONNAMEs

* implicit-casts:false on flutter_tools

* use castStringKeyedMap

* address review comments

* address review comments

* fix issues after rebase

This reverts commit 3597bae6.

...because otherwise, processes that think they're manipulating your
filesystem will be doing crazy things the test is ignoring, leading to
(at best) failures and (at worst) flakes or disk corruption.

[BUG] Process all children of intent-filter instead of just the first one to identify default activity (#40029)

Applying our style guide:
https://github.com/flutter/flutter/wiki/Style-guide-for-Flutter-repo#have-good-hygiene-when-using-temporary-directories

We were using the `defaults` command-line utility to parse
Plist files, but it was never supported by Apple, and it
appears that in an upcoming OS release, it will be less likely
to work:

> WARNING: The defaults command will be changed in an upcoming
> major release to only operate on preferences domains. General
> plist manipulation utilities will be folded into a different
> command-line program.

Fixes https://github.com/flutter/flutter/issues/37701

Move tools tests into a general.shard directory in preparation to changing how we shard tools tests (#36108)

This relands flutter/flutter#33163 with a fix to the integration_ui test.