Update CODEOWNERS to include rum-mobile-android

[plousada]

What does this PR do?

Update codeowners file to include @DataDog/rum-mobile-android team

Motivation

What inspired you to submit this pull request?

Additional Notes

Anything else we should know when reviewing?

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 #213 (258302a) into develop (bfff839) will not change coverage. The diff coverage is n/a.

Additional details and impacted files

```diff @@ Coverage Diff @@ ## develop #213 +/- ## ========================================== Coverage 86.05% 86.05% Complexity 181 181 ========================================== Files 21 21 Lines 588 588 Branches 78 78 ========================================== Hits 506 506 Misses 55 55 Partials 27 27 ```