Add a retry decorator to the GitHub log downloader.

[jonsimantov]

Description

Provide details of the change, and generalize the change in the PR title above.

This should fix the flaky GMA iOS "crash/timeout" test, as the error is often just that it's unable to fetch the test results (possibly because that test runs so quickly). Example log

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Testing

Describe how you've tested these changes. Link any manually triggered Integration tests or CPP binary SDK Packaging Github Action workflows, if applicable.

Ran GMA integration test on iOS a number of times without issues. Considering this usually flakes at least every other day, I'm willing to say this helps.

Also running integration tests in this PR, and packaging workflow, to ensure that the added Python module dependency doesn't break any of our build/test environments.

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Type of Change

Place an x the applicable box:

• Bug fix. Add the issue # below if applicable.
• New feature. A non-breaking change which adds functionality.
• Other, such as a build process or documentation change.

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Notes

• Bug fixes and feature changes require an update to the Release Notes section of release_build_files/readme.md.
• Read the contribution guidelines CONTRIBUTING.md.
• Changes to the public API require an internal API review. If you'd like to help us make Firebase APIs better, please propose your change in a feature request so that we can discuss it together.

[github-actions]

Integration test with FLAKINESS (succeeded after retry)

Requested by @jonsimantov on commit af4e2b2
Last updated: Fri Jul 14 13:41 PDT 2023
View integration test log & download artifacts

Failures	Configs
app_check	[TEST] [FLAKINESS] [Android] [1/3 os: macos] [1/2 android_device: emulator_ftl_target] (1 failed tests)   CRASH/TIMEOUT
messaging	[TEST] [FLAKINESS] [Android] [1/3 os: ubuntu] [1/2 android_device: android_target] (1 failed tests)   CRASH/TIMEOUT

Add flaky tests to go/fpl-cpp-flake-tracker

[jonsimantov]

All tests and packaging passed, this is ready for review.