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.

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

* Fix license path for missing sdkmanager

* Cirrus re-run...

* Fix condition check

* rename props, add docs, rename method

* fix tests after param changes

* Fix weird path for flutter run and add tests

* remove print, fix tests

* Detect Android SDK 28/28.0.3

* revert minimumAndroidSdkVersion const change

* enable lint unnecessary_new

* fix tests

* fix tests

* fix tests

* First step in Flutter Doctor refactor. Assigns categories to all validators.

* Revert "Roll engine e54bc4ea1832..a84b210b3d26 (6 commits) (#20453)"

This reverts commit 05c2880a.

* Split iOS and Android workflows into workflow and validator classes.

* Change ValidatorCategory to handle standalone validators that share a
category (e.g. IntelliJ).

Also make Android Studio and Android toolchain use separate categories.

At this stage, flutter doctor output matches what it was previously.
(The summary() method itself has not yet been changed )

* Change doctor summary code to support validator categories.

Output is still unchanged.

* Handle small formatting issues.

* Flip Flutter category's isGroup field to false until it's actually
needed.

* Revert auto-generated formatting changes to keep those lines from
muddying the pull.

* Small fixes pointed out by analyzer.

* Properly fix analyzer issues around const constructors.

* Small changes to address comments.

* Add tests to verify grouped validator behavior and validationtype
merging.

* Update doctor.dart

* Add comments for clarification.

All temporary directory start with `flutter_` and have their random component separated from the name by a period, as in `flutter_test_bundle.YFYQMY`.

I've tried to find some of the places where we didn't cleanly delete temporary directories, too. This greatly reduces, though it does not entirely eliminate, the directories we leave behind when running tests, especially `flutter_tools` tests.

While I was at it I standardized on `tempDir` as the variable name for temporary directories, since it was the most common, removing occurrences of `temp` and `tmp`, among others.

Also I factored out some common code that used to catch exceptions that happen on Windows, and made more places use that pattern.

* Upgrade everything except matcher.
* Roll matcher (and test)
* Adjust tests that depend on flutter:test directly to depend on a shim
* Require use of package:test shim and remove other references to package:test

Fixes https://github.com/flutter/flutter/issues/16332

* Revert "Revert "Add android license verification to doctor and some refactoring" (#14727)"

This reverts commit d2602947.

* Add tests, fix sdkManagerEnv and use it consistently, and rearrange Status object model

* AnsiSpinner needs to leave the cursor where it found it.

* fix tests

* Const constructor warning only shows up on windows...?

* Avoid crash if we can't find the home directory

* Make pathVarSeparator return a string in the mock

* Implement review comments

* Fix out-of-order problem on stop

Reports from that commit included:

* Doctor hanging
* Doctor prompting to install JDK
* AnsiStatus.cancel() printing elapsed time and extra newline
* Printing extra spinner character at the end of each line

* Initial version, seems to work

* Unit test for android license checker

* Cleanups

* Windows analyzer wants const.

* Refinements to timeout

* review comments

* Forgot a nit

Adds unit tests for AndroidWorkflow.runLicenseManager().