test: synced androidx gradle versions to the same version as the android test

[breautek]

Platforms affected

Android

Motivation and Context

Fixes androidx test versions, who was still on gradle 4 and android gradle plugin 3.5.3, inconsistent with its android test sibling.

Description

Upgrade gradle version pins

Testing

Ran npm test

Checklist

• I've run the tests to see all new and existing tests pass
• I added automated test coverage as appropriate for this change
• Commit is prefixed with (platform) if this change only applies to one platform (e.g. (android))
• If this Pull Request resolves an issue, I linked to the issue in the text above (and used the correct keyword to close issues using keywords)
• I've updated the documentation if necessary

[codecov-io]

Codecov Report

Merging #959 into master will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff           @@
##           master     #959   +/-   ##
=======================================
  Coverage   65.53%   65.53%           
=======================================
  Files          21       21           
  Lines        1828     1828           
=======================================
  Hits         1198     1198           
  Misses        630      630           

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