fix: Fix NPE in GcToolResults

[pawelpasterz]

Fixes #1649

PR adds NPE handling when fetching results

Test Plan

How do we know the code works?

1. build workflows finish with success
2. IT pass

[github-actions]

CLA Assistant Lite bot All contributors have signed the CLA ✍️ ✅

[pawelpasterz]

@flank-it

[github-actions]

Integration tests succeed for all OSes ✅
Windows Build scan:
MacOS Build scan: https://gradle.com/s/rdavqfbv6i4ke
Linux Build scan: https://gradle.com/s/pwnahsaqa2ckk
Workflow run https://github.com/Flank/flank/actions/runs/623910795

[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: 2021-03-05 09:11:38
Buildscan url for ubuntu-workflow run 623909982
https://gradle.com/s/uwlabrcxmyava