Fix restore / build issue

[clairernovotny]

Restore and build cannot be invoked at the same time. Restore must be done with a switch.

Description of Change

Fixes incorrect msbuild usage.

Describe your changes here.

Bugs Fixed

• Related to issue #
  See this issue: We should generate an error or warning if Restore and Build targets are run in the same evaluation dotnet/sdk#2170

Provide links to issues here. Ensure that a GitHub issue was created for your feature or bug fix before sending PR.

API Changes

List all API changes here (or just put None), example:

Added:

• string - string Class.Property { get; set; }
• void Class.Method();

Changed:

• object Cell.OldPropertyName => object Cell.NewPropertyName

Behavioral Changes

Describe any non-bug related behavioral changes that may change how users app behaves when upgrading to this version of the codebase.

PR Checklist

• Has tests (if omitted, state reason in description)
• Has samples (if omitted, state reason in description)
• Rebased on top of master at time of PR
• Changes adhere to coding standard
• Updated documentation (see walkthrough)

[dend]

✅ Validation status: passed

File	Status	Preview URL	Details
build.ps1	✅Succeeded

For more details, please refer to the build report.

Note: If you changed an existing file name or deleted a file, broken links in other files to the deleted or renamed file are listed only in the full build report.

[jamesmontemagno]

build