Change Xcode project developmentRegion to 'en' and plist CFBundleDevelopmentRegion to DEVELOPMENT_LANGUAGE (#34293)

* move flutter_assets to App.framework

* Roll engine to 05fee4eeee0ff6b219b1fcc394371e5f6963cc46

05fee4eee Update default flutter_assets path for iOS embedding (flutter/engine#7518)
02205db01 Roll src/third_party/skia 5d052dac3ac1..02738a86e5fd (4 commits) (flutter/engine#7541)
af907c074 Roll src/third_party/skia 5c7a3ac0e214..5d052dac3ac1 (7 commits) (flutter/engine#7540)
dde286673 IWYU to get SkFontMetrics (flutter/engine#7539)

This reverts commit d8db70af.

* move flutter_assets to App.framework

* remove flutter_assets references from all pbxproj files checked in

* Use Xcode build configurations to drive Flutter build mode

* Proper check wrt local_engine, print error if profile mode misisng

* Remove unused code, update tests, fix template problem, update warning

* fix up warning

* add explanatory dev comment

* fix whitespace

* missing words, change lambda arrow to function body

* error indentation

* Test early exits for xcode_backend.sh

* only on macOS, use right test

* Update error messages

* case insensitive compare for build config

* Update gallery podfile

* update projects to add profile configuration

* make compatible with flavors

* add missing plist files

* add FLUTTER_FRAMEWORK_DIR back, set swift version for profile, tell Podfile about profile

* Revert "Update templates (#23698)"

This reverts commit 5b0de6d6.

* Revert "Verify that date/number translations exist for all supported languages (#23692)"

This reverts commit 3449edf2.

* Revert "Reland Xcode backend refactor (#23574)"

This reverts commit 7270f284.

* Use Xcode build configurations to drive Flutter build mode

* Proper check wrt local_engine, print error if profile mode misisng

* Remove unused code, update tests, fix template problem, update warning

* fix up warning

* add explanatory dev comment

* fix whitespace

* missing words, change lambda arrow to function body

* error indentation

* Test early exits for xcode_backend.sh

* only on macOS, use right test

* Update error messages

* case insensitive compare for build config

* Update gallery podfile

* update projects to add profile configuration

* make compatible with flavors

* add missing plist files

Generated.xcconfig is only required at build time for iOS apps. In the
flutter create project template and example apps, Generated.xcconfig was
previously marked as a resource to be bundled into the built app.

Updates all example projects to build as universal binaries that run on
both armv7 and arm64 now that we support both platforms on iOS.

* wip

* wip

* delete main.m

* readd main.m

* update to use new channel api

* update android

* removed android/

* remove debug print

* remomved main.m

* Update year in copyright

* break long line and update name

* mit comments

* update examples/README

* break line

* update README

* update test