Updating Ubuntu 20.04 to Ubuntu 22.04 for OneFuzz defaults

[AdamL-Microsoft]

Summary of the Pull Request

Updating documentation and defaults in OneFuzz code for Ubuntu 20.04 to be Ubuntu 22.04

PR Checklist

• [ ] Applies to work item: #xxx
• [ ] CLA signed. If not, go over here and sign the CLI.
• [ ] Tests added/passed
• [ ] Requires documentation to be updated
• [ ] I've discussed this with core contributors already. If not checked, I'm ready to accept this work might be rejected in favor of a different grand plan. Issue number where discussion took place: #xxx

Info on Pull Request

What does this include?

Validation Steps Performed

How does someone test & validate?

[codecov-commenter]

Codecov Report

Merging #3570 (a8a0e70) into main (d792b3b) will decrease coverage by 0.01%. The diff coverage is 100.00%.

@@            Coverage Diff             @@
##             main    #3570      +/-   ##
==========================================
- Coverage   39.01%   39.00%   -0.01%     
==========================================
  Files         302      302              
  Lines       36954    36954              
==========================================
- Hits        14417    14415       -2     
- Misses      22537    22539       +2     

Files	Coverage Δ
...ApiService/ApiService/onefuzzlib/ImageReference.cs	42.52% <100.00%> (ø)

... and 1 file with indirect coverage changes