Add exponential backoff to connection checks in docker-tests

[SrdjanLL]

Description

Add exponential backoff to the retry mechanism of availability checks in docker-tests.

• There's a good chance this reduces flaky execution of docker-tests in the future 🤞🏻.
  • I have them failing on two of my PRs (Use semantic convention attribute for cloud region for botocore API calls #3474 and Ensure spans complete on early stream closure for Bedrock Streaming APIs #3481).

Type of change

Please delete options that are not relevant.

• Bug fix (non-breaking change which fixes an issue)

How Has This Been Tested?

• Ran docker-tests job using local github action runner (act)
• Confirmed on my fork the docker-tests is failing.

Does This PR Require a Core Repo Change?

• Yes. - Link to PR:
• No.

Checklist:

See contributing.md for styleguide, changelog guidelines, and more.

• Followed the style guidelines of this project
• [] Changelogs have been updated
• Unit tests have been added
• Documentation has been updated