[flutter_tools] Add documentation to "cmdline-tools component is missing" doctor validation error (#83356)

This reverts commit 547ed88a.

* opt out the flutter tool

* oops EOF

* fix import

* Update tool_backend.dart

* Update daemon_client.dart

* fix more

More work to prevent current #2 crash issue on stable. If adb is not located do not list/create android devices.

Avoid creating AndroidDevice discovery if the SDK cannot be located. Previously the tool would use which/where adb, however this required us to handle the AndroidSdk class being potentially null - which required an additional layer of indirection around all access. Sometimes these were forgotten leading to NPEs.

In general, not much can be done with an Android Device if the actual SDK is not installed.

Reland with fixed code + tests for null SDK + adb in AndroidDeviceDiscovery

Revert "[flutter_tools] avoid creating Android Devices if AndroidSDK cannot be found (#64524)" (#64602)

This reverts commit 47596c62.

Avoid creating AndroidDevice discovery if the SDK cannot be located. Previously the tool would use which/where adb, however this required us to handle the AndroidSdk class being potentially null - which required an additional layer of indirection around all access. Sometimes these were forgotten leading to NPEs.

In general, not much can be done with an Android Device if the actual SDK is not installed.

* 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

...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.

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

* add trailing commas on list/map/parameters

* add trailing commas on Invocation with nb of arg>1

* add commas for widget containing widgets

* add trailing commas if instantiation contains trailing comma

* revert bad change

* Allow for gradle downloading missing SDK assets if SDK licenses are present.

*  Improvements for windows testing

This reverts commit 6f5e88a5.