GIT_BRANCH override supported on azure pipelines with gitversion 5.x

[Ninho67]

Description

Added support for GIT_BRANCH environment variable in Azure pipeline builds with gitversion 5.x

Related Issue

#4662

Motivation and Context

Solves multi-repo build situations on azure pipelines without being forced to upgrade to gitversion 6.x,
Upgrading to gitversion 6.x breaks the versionning locally on Visual Studio (Windows).

How Has This Been Tested?

Tested on azure by adding the env variable GIT_BRANCH as follows:

- task: DotNetCoreCLI@2
  displayName: 'Build project 1'
  env:
     GIT_BRANCH: '${{parameters.SpotBranch}}'
  ...

Screenshots (if appropriate):

Checklist:

• [ x] My code follows the code style of this project.
• My change requires a change to the documentation.
• I have updated the documentation accordingly.
• [x ] I have added tests to cover my changes.
• [x ] All new and existing tests passed.

[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud