Adds Retry Policy behavior to the Java SDK

[mpodwysocki]

Things to consider before you submit the PR:

• [x] Are tests passing locally?
• [x] Are the files formatted correctly?
• [ ] Did you add unit tests?
• [ ] Did you test your change with either the sample apps that are included in the repository or with a blank app that uses your change?

Description

This PR includes a basic retry policy for the Java SDK. In order to accomplish this, we needed to migrate to the Apache HTTP Core 5.x release from 4.x. This PR updates the import statements with their 5.x as well as introducing the BasicRetryPolicy.

Related PRs or issues

N/A

Misc

N/A