Fix test report and code coverage upload

[cwperks]

Description

This PR fixes uploads to codecov and general uploads of artifacts to Github. While working on #736, I noticed that uploads were hitting the rate limit and failing.

==> Uploading reports
    url: https://codecov.io
    query: branch=main&commit=c643111d76f63eadd5fe1196844f96a84df530bb&build=11[47](https://github.com/opensearch-project/performance-analyzer/actions/runs/11473403760/job/31927585948#step:9:48)3403760&build_url=https%3A%2F%2Fgithub.com%2Fopensearch-project%2Fperformance-analyzer%2Factions%2Fruns%2F11473403760&name=&tag=&slug=opensearch-project%2Fperformance-analyzer&service=github-actions&flags=&pr=&job=Java+CI&cmd_args=f
->  Pinging Codecov
https://codecov.io//upload/v4?package=bash-1.0.6&token=<hidden>&package=bash-1.0.6&token=&branch=main&commit=c643111d76f63eadd5fe1196844f96a84df530bb&build=11473403760&build_url=https%3A%2F%2Fgithub.com%2Fopensearch-project%2Fperformance-analyzer%2Factions%2Fruns%2F11473403760&name=&tag=&slug=opensearch-project%2Fperformance-analyzer&service=github-actions&flags=&pr=&job=Java+CI&cmd_args=f
{"message":"Rate limit reached. Please upload with the Codecov repository upload token to resolve issue. Expected time to availability: 2501s."}
{"message":"Rate limit reached. Please upload with the Codecov repository upload token to resolve issue. Expected time to availability: 2[49](https://github.com/opensearch-project/performance-analyzer/actions/runs/11473403760/job/31927585948#step:9:50)9s."}
{"message":"Rate limit reached. Please upload with the Codecov repository upload token to resolve issue. Expected time to availability: 2497s."}
{"message":"Rate limit reached. Please upload with the Codecov repository upload token to resolve issue. Expected time to availability: 2495s."}
{"message":"Rate limit reached. Please upload with the Codecov repository upload token to resolve issue. Expected time to availability: 2492s."}
{"message":"Rate limit reached. Please upload with the Codecov repository upload token to resolve issue. Expected time to availability: 2490s."}

This PR changes the upload step to use the GHA for uploading to codecov.

Workflow where it failed: https://github.com/opensearch-project/performance-analyzer/actions/runs/11473403760/job/31927585948

Check List

• New functionality includes testing.
• New functionality has been documented.
• API changes companion pull request created.
• Commits are signed per the DCO using --signoff.
• Public documentation issue/PR created.

By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license.
For more information on following Developer Certificate of Origin and signing off your commits, please check here.

[Gaganjuneja]

Waiting for builds to complete.

[cwperks]

Upload still failed. Looking into it.