fix: Add fallback when cannot get reference to avoid failing tests on release

[piotradamczyk5]

Test Plan

How do we know the code works?

When cannot get the branch name from git or HEAD_REF is missing. Tests artifacts are downloaded for master branch

[mergify]

Title does not follow the guidelines of Conventional Commits.
Please adjust title before merge and use one of following prefix:

• build - Changes that affect the build system or external dependencies (dependencies update)
• ci - Changes to our CI configuration files and scripts (basically directory .github/workflows)
• docs - Documentation only changes
• feat - A new feature
• fix - A bug fix
• chore - Changes which does not touch the code (ex. manual update of release notes). It will not generate release notes changes
• refactor - A code change that contains refactor
• style - Changes that do not affect the meaning of the code (white-space, formatting, missing semi-colons, etc)
• test - Adding missing tests or correcting existing tests and also changes for our test app
• perf - A code change that improves performance (I do not think we will use it)

[github-actions]

Timestamp: 2020-12-01 21:47:43
Buildscan url for ubuntu-workflow run 394771811
https://gradle.com/s/mqvga6yy7aiiu

[codecov-io]

Codecov Report

Merging #1369 (c0abf7f) into master (106cb4f) will not change coverage.
The diff coverage is n/a.

@@            Coverage Diff            @@
##             master    #1369   +/-   ##
=========================================
  Coverage     77.81%   77.81%           
  Complexity      705      705           
=========================================
  Files           244      244           
  Lines          4693     4693           
  Branches        901      901           
=========================================
  Hits           3652     3652           
  Misses          550      550           
  Partials        491      491