[exporter/awss3exporter] Add canned_acl as an input

[kevthompson]

Description

Adds an additional input canned_acl to use when uploading S3 objects. Followed the same patterns as the storage_class option.

Link to tracking issue

Fixes #37935

Testing

Updated config in all test files and added testdata/config-s3_canned-acl.yaml to validate input.

Tested against personal S3 bucket, with various canned ACLs & with ACLs disabled at the bucket level

Documentation

Updated README to include new input with default value.

[linux-foundation-easycla]

The committers listed above are authorized under a signed CLA.

• ✅ login: kevthompson / name: Kevin Thompson (fc475ba, 0c2e326, ceeec99, 125f594, fe395c2, 61cb3ac, 8f16e40, 914d5a7, e7c2620, 28cc668, fa49b11)

[atoulme]

Changes look good to me, but canned seems like it would be too buttery: https://gaushalausa.org/product/a2-ghee-2lbs/

[kevthompson]

Need to build locally & test against an actual AWS bucket still, may also need to allow an empty string for the ACL.

[kevthompson]

Need to build locally & test against an actual AWS bucket still, may also need to allow an empty string for the ACL.

Validated against my own s3 bucket & behavior all seems correct. If ACLs are disabled at the bucket level, uploads work unless you specify an ACL.

[atoulme]

I am kicking the build, please hold off merging main, I have to kick the build off every time you do :)