Add x-amz-server-side-encryption header for AES256 SSE without customer keys (non SSE-C)

[85danf]

Problem

See #770

Solution

The code in this PR adds the x-amz-server-side-encryption header in cases where SSE is configured to be AES256 but not customer key was provided.

Does this solution apply anywhere else?

• yes
• no

If yes, where?

The following versions (and onwards) are affected, I'm not sure about this repo's patch strategy so I opened it on the latest branch.

• 10.5.6
• 10.4.8
• 10.3.10
• 10.2.14
• 10.1.15
• 10.0.26

Test Strategy

Built locally and tested on our environment.

Testing done:

• Unit tests
• Integration tests
• System tests
• Manual tests

Release Plan

[cla-assistant]

Thank you for your submission! We really appreciate it. Like many open source projects, we ask that you all sign our Contributor License Agreement before we can accept your contribution.
8 out of 13 committers have signed the CLA.

✅ pbadani
✅ ashoke-cube
✅ aniketshrimal
✅ dttung2905
✅ rohits64
✅ subhashiyer9
✅ huizheng278
✅ 85danf
❌ ConfluentJenkins
❌ sp-gupta
❌ Enigma25
❌ b-goyal
❌ ConfluentSemaphore
_{You have signed the CLA already but the status is still pending? Let us recheck it.}

[cla-assistant]

Thank you for your submission! We really appreciate it. Like many open source projects, we ask that you sign our Contributor License Agreement before we can accept your contribution.
_{You have signed the CLA already but the status is still pending? Let us recheck it.}

[85danf]

Wrong branch