CI builds for windows desktop can fail if Visual Studio installation is incomplete #154453

For example: https://ci.chromium.org/ui/p/flutter/builders/try/Windows%20build_tests_1_7/16262/infra

Note:

1. In step 10, we check if Visual Studio is already installed (https://flutter.googlesource.com/recipes/+/663697664d556d1e8725ac6ab2d53dd972b5145d/recipe_modules/os_utils/api.py#837). We are only looking for the version.
2. However, the actual output of vswhere.exe has the field "isComplete": false https://logs.chromium.org/logs/flutter/buildbucket/cr-buildbucket/8738150602716059217/+/u/VSBuild/Detect_installation/json.output
3. The tool parses this isComplete field and will fail to build a windows app if it is not complete:

   flutter/packages/flutter_tools/lib/src/windows/visual_studio.dart

   Line 545 in 7aace1c

   isComplete: details['isComplete'] as bool?,