Add RequestAcceptEncoding interceptor for compression

[sincejune]

Problem

Currently, the compression flag(connection.compression) is not working due to the missing of RequestAcceptEncoding interceptor in HTTP client.

Solution

This PR added RequestAcceptEncoding interceptor in HTTP client builder to apply Accept-Encoding: gzip,deflate header.

Does this solution apply anywhere else?

• [x] yes
• [ ] no

If yes, where?

This interceptor should affect all requests to ElasticSearch which used the ConfigCallbackHandler handler.

Test Strategy

Testing done:

• [ ] Unit tests
• [ ] Integration tests
• [ ] System tests
• [x] Manual tests

Release Plan

[ghost]

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[sincejune]

[clabot:check]

[ghost]

@confluentinc It looks like @sincejune just signed our Contributor License Agreement. :+1:

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