This reverts commit d056500b.

This reverts commit 31de052e.

This reverts commit e2490f29.

Update samples to use repo analysis options, Fix sample templates and a ton of analyzer issues (#77868)

My yearly pass to fix spelling errors in the API dartdocs.

* migrate some cupertino files to nullsafety

* address review comments

* address review comments

This follows https://github.com/flutter/flutter/pull/59364 and cl/319911104

FittedBox is still default to hardEdge clip as new FittedBox is added to Google very quickly. Let's first roll other part of changes into Google first.

* add language version 2.8 in packages/flutter

* enable non-nullable analyzer flag

This reverts commit 2132a0c7.

This reverts commit 69080e07.

* 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

* make BuildContext.{ancestorStateOfType,ancestorRenderObjectOfType,rootAncestorStateOfType} generic

* make BuildContext.inheritFromWidgetOfExactType generic

* make BuildContext.ancestorInheritedElementForWidgetOfExactType generic

* make BuildContext.ancestorWidgetOfExactType generic

* fix snippet

* bump scoped_model on temp version

* update names

* Revert "bump scoped_model on temp version"

This reverts commit d1fcbba028cdb07f44738d1652391692d1ea5ec0.

* address review comments

* fix ci

* address review comments

* repeat the deprecation notice

* fix uppercase

* use of recommanded deprecation syntax

* address review comment

Replace CupertinoSliverRefreshControl.onRefresh's then callback with whenCompleted callback, so when onRefresh completes with error the sliver refresh control retracts like when it completes with value.

- Fixed the bug where CupertinoRefreshControl doesn't work in the gallery demo on Android.
- Updated documentation on CupertinoRefreshControl
- Added comments to the gallery demo
- Added concrete examples to ScrollPhysics

* 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

* enable lint unnecessary_new

* fix tests

* fix tests

* fix tests

It was causing problems rolling Flutter into Fuchsia

* re-enable lint unnecessary_const

* remove trailling whitespaces

* remove unnecessary const (after merge)

This reverts commit cc1cf13e.