* add language version 2.8 in packages/flutter

* enable non-nullable analyzer flag

* replace simple Container(w & h) with SizedBox

* address review comments

* address review comments

This reverts commit 2132a0c7.

This reverts commit 69080e07.

* reland "Refactors global key duplication detection (#46183)"

This reverts commit d2b66dbf.

* fix test

This reverts commit 340b193f.

* 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

Fixes #42049.

* add missing trailing commas

* add more missing trailing commas

* add more and more missing trailing commas

Make font semibold when isDefaultAction is true in CupertinoDialogAction

* enable lint unnecessary_new

* fix tests

* fix tests

* fix tests

Fixes #21250

Deprecated CupertinoDialog in favor of a new widget called CupertinoPopupSurface. (#20397)

Rewrote CupertinoAlertDialog to look nearly identical to an alert dialog in iOS. This includes considerations for blur, translucent white background color, button sizing, gap dividers between buttons, and text scaling layout behavior. (#18381)

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.