Fix caches for RNTester (#49791)

Summary:
Pull Request resolved: https://github.com/facebook/react-native/pull/49791

The cache for RNTester is broken because the matrix parameters used to test RNTester are not part of the job_id that is used to create the cache keys to restore the Podfile.lock.

This means that we have a race condition on which job of the matrix manages to save the cache. However, those caches are not always valid for the other jobs that presents different matrix parameters.

This change should fix the issue.

## Changelog:
[Internal] - Fix test-rn-tester cache Cache

Reviewed By: cortinico

Differential Revision: D70493507

fbshipit-source-id: 1db6e00507b3e9abe4400831ee1b048c620b9102