Bump 2.21.2 - Apply imds patch & upgrade to enumerated cherry-pick patches

[matthewfala]

Signed-off-by: Matthew Fala [email protected]

Issue #, if available:
This patch resolves the IMDSv1 fallback error mentioned in the following issue: #259.

Description of changes:
Introduces a patch that allows for graceful IMDSv1 fallback if IMDSv2 is not available due to the hop limit error.
Introduces network timeout dependency feature to Fluent Bit which we are working on getting merged upstream.

By submitting this pull request, I confirm that you can use, modify, copy, and redistribute this contribution, under the terms of your choice.

[matthewfala]

This cherry picks commits enumerated in added AWS_FLB_CHERRY_PICKS file.

[PettitWesley]

Can we just use the old strategy of having a specific branch? It makes it easy to check that we did everything correctly and released exactly the right code- it's simpler to code review.

[hossain-rayhan]

Yea, I also prefer to cut a release from a single branch.

[PettitWesley]

Discussed with Matt, I am okay with using this approach after the addition of the git log statement below which will print the commits that were added to the final branch that is built

[zhonghui12]

In this way, we should remember to check the git log result in our pipeline console even if build stage succeeds.

[matthewfala]

Here's what to look out for:

=> => # Cherry Pick Patch Summary:                                                                                                                                                                    
=> => # Commit 1 -- 88571668 tls: Issue #4098 Fix error handling for OpenSSL apis                                                                                                                     
=> => # Commit 2 -- dacbff5d downgrade mbedtls to 2.24.0                                                                                                                                              
=> => # Commit 3 -- cdccb530 io: revised support timeout on synchronous calls                                                                                                                         
=> => # Commit 4 -- 028536b8 io: default to old net_io_read                                                                                                                                           
=> => # Commit 5 -- 60098b3d aws: revised imds fallback to v1 if token request fails

We need to make sure that these commits match the commits listed here:
https://github.com/aws/aws-for-fluent-bit/blob/8a2af50d2dcb7f53fdce2eb3610d4cc1a4a0a3fc/AWS_FLB_CHERRY_PICKS