Update branding to 7.0.1 (#44768)

- Update branding to 7.0.1
- Complete 7.0.1 branding
  - change label to "servicing"
  - check in 7.0.0 PackageOverrides.txt and PlatformManifest.txt files
- Special case current .NET SDK version
  - use incoming runtime even though this is a servicing build

Co-authored-by: Doug Bunting <6431421+dougbu@users.noreply.github.com>