RUM-2271: Add files under kotlin source set to the repository information

[0xnm]

What does this PR do?

AGP 7.0.0 introduced the additional kotlinDirectories to explicitly separate kotlin and java source sets, so if all the files are under kotlin, we were missing it. This PR fixes that.

Review checklist (to be filled by reviewers)

• Feature or bugfix MUST have appropriate tests (unit, integration, e2e)
• Make sure you discussed the feature or bugfix with the maintaining team in an Issue
• Make sure each commit and the PR mention the Issue number (cf the CONTRIBUTING doc)

[codecov-commenter]

Codecov Report

Merging #212 (1537f56) into develop (0fd0071) will decrease coverage by 0.97%.
The diff coverage is 28.57%.

Additional details and impacted files

@@              Coverage Diff              @@
##             develop     #212      +/-   ##
=============================================
- Coverage      79.05%   78.08%   -0.97%     
- Complexity       186      187       +1     
=============================================
  Files             22       22              
  Lines            654      666      +12     
  Branches          81       85       +4     
=============================================
+ Hits             517      520       +3     
- Misses           107      117      +10     
+ Partials          30       29       -1     

Files	Coverage Δ
...og/gradle/plugin/internal/GitRepositoryDetector.kt	97.06% <100.00%> (ø)
...n/com/datadog/gradle/plugin/internal/ProjectExt.kt	100.00% <ø> (ø)
...com/datadog/gradle/plugin/DdAndroidGradlePlugin.kt	54.65% <23.08%> (-2.22%)	⬇️

The base branch was changed.