re-land "Retry cURL downloads"

[christopherfujino]

Description

This is a re-land of #50731, which was reverted because dart infra's version of curl didn't support --retry-connrefused. This re-lands the retry flags and leaves off the --retry-connrefused flag.

Related Issues

#50730

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[jmagman]

Did we ever get an answer to #50731 (comment) from @zanderso?

Any reason not to keep the default exponential backoff behavior?

[christopherfujino]

Did we ever get an answer to #50731 (comment) from @zanderso?

Any reason not to keep the default exponential backoff behavior?

Nope. @fkorotkov, should we not use the default behavior?

[fkorotkov]

@christopherfujino 🤷‍♂ yeah, let's keep it simple then with just retry count.

[christopherfujino]

@jmagman removed explicit 5 second delay, PTAL