Fixes the performance issue with tree-shake-icons and filters to ttf mime type. Does not change default or error behavior.

Revert "[flutter_tools] Allow providing dart-defines to Android, iOS, macOS builds (#51714)" (#52041)

This reverts commit ee60eeea.

* 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/lib

* address review comments

* use castStringKeyedMap

* introduce {bool,string,strings}Arg

* fix ci

This reverts commit bd52a78c.

This reverts commit 52ae9968.

Reland: Ensure that flutter run/drive/test/update_packages only downloads required artifacts  (#30254)

Revert "Ensure that flutter run/drive/test/update_packages only downloads required artifacts (#30075)" (#30232)

This reverts commit 6a7f231d.