Enable track widget creation when generating Generated.xcconfig - #101123

…ig (flutter/flutter#101123)

…ig (flutter/flutter#101123)

…ig (flutter/flutter#101123)

…ig (flutter/flutter#101123)

…le (flutter#196078)

Registers `BuildInfoOptions.trackWidgetCreation` in
`AppleBuildOptionsBundle` so Apple build subcommands (`build ios`,
`build ipa`, and `build macos`) register `--[no-]track-widget-creation`
(defaulting to on). Note that `--profile` AOT builds for `build ios` and
`build ipa` will also now compile with `--track-creation-locations` by
default (unless `--no-track-widget-creation` is passed), matching `build
macos`, `build apk`, `build appbundle`, and `flutter run --profile`.

This regression was originally introduced in
flutter#56094 (first shipped in Flutter
1.20.0). Prior to flutter#56094,
`xcodeproj.dart` omitted `TRACK_WIDGET_CREATION` from
`Generated.xcconfig` when `buildInfo.trackWidgetCreation` was `false`,
and `KernelSnapshot` enabled widget creation tracking whenever
`TrackWidgetCreation` was not `'false'`.
flutter#56094 switched `xcodeproj.dart`
to `buildInfo.toEnvironmentConfig()`, which unconditionally writes
`TRACK_WIDGET_CREATION=${trackWidgetCreation}`.

In flutter#101123 (fixing
flutter#94681), `BuildInfo.debug` was
updated to set `trackWidgetCreation: true`, which fixed
`Generated.xcconfig` for projects built directly from Xcode after
`flutter create` or `flutter pub get` (while `flutter run` already
registered `--track-widget-creation`). However, `BuildIOSCommand`
constructs its `BuildInfo` via `FlutterCommand.getBuildInfo()` and never
registered `--track-widget-creation` (an omission later carried forward
into `AppleBuildOptionsBundle` in
flutter#192818), so running `flutter
build ios --debug` overwrote `Generated.xcconfig` with
`TRACK_WIDGET_CREATION=false` and caused the first hot reload after
`flutter attach` to fail with `Lookup failed: _location`.

Previous output:
```
+13: ios build debug config-only writes TRACK_WIDGET_CREATION=true to Generated.xcconfig by default

Expected: contains 'TRACK_WIDGET_CREATION=true'
  Actual: '// This is a generated file; do not edit or check into version control.\n'
            'FLUTTER_ROOT=/usr/local/google/home/bkonyi/.gemini/jetski/worktrees/flutter/issue-195792\n'
            'FLUTTER_APPLICATION_PATH=/\n'
            'FLUTTER_FRAMEWORK_SWIFT_PACKAGE_PATH=/ios/Flutter/ephemeral/Packages/.packages/FlutterFramework\n'
            'COCOAPODS_PARALLEL_CODE_SIGN=true\n'
            'FLUTTER_TARGET=lib/main.dart\n'
            'FLUTTER_BUILD_DIR=build\n'
            'FLUTTER_BUILD_NAME=1.0.0\n'
            'FLUTTER_BUILD_NUMBER=1\n'
            'EXCLUDED_ARCHS[sdk=iphonesimulator*]=i386\n'
            'EXCLUDED_ARCHS[sdk=iphoneos*]=armv7\n'
            'DART_DEFINES=RkxVVFRFUl9WRVJTSU9OPTAuMC4w,RkxVVFRFUl9DSEFOTkVMPW1hc3Rlcg==,RkxVVFRFUl9HSVRfVVJMPWh0dHBzOi8vZ2l0aHViLmNvbS9mbHV0dGVyL2ZsdXR0ZXIuZ2l0,RkxVVFRFUl9GUkFNRVdPUktfUkVWSVNJT049MTExMTE=,RkxVVFRFUl9FTkdJTkVfUkVWSVNJT049YWJjZGU=,RkxVVFRFUl9EQVJUX1ZFUlNJT049MTI=\n'
            'DART_OBFUSCATION=false\n'
            'TRACK_WIDGET_CREATION=false\n'
            'TREE_SHAKE_ICONS=false\n'
            'PACKAGE_CONFIG=/.dart_tool/package_config.json\n'
            ''
   Which: does not contain 'TRACK_WIDGET_CREATION=true'
```

Current output:
```
00:00 +0: loading /usr/local/google/home/bkonyi/.gemini/jetski/worktrees/flutter/issue-195792/packages/flutter_tools/test/commands.shard/hermetic/build_ios_test.dart
00:00 +0: (setUpAll)
00:00 +0: ios build debug config-only writes TRACK_WIDGET_CREATION=true to Generated.xcconfig by default
00:00 +1: (tearDownAll)
00:00 +1: All tests passed!
```

Fixes flutter#195792