fix: reduce memory pressure while uploading files

[sobolk]

Description of changes

This PR is a partial revert of https://github.com/aws-amplify/amplify-cli/pull/13493/files which caused #13681 .

I.e. using s3.upload API for all uploads puts a memory pressure due to aws/aws-sdk-js#2552 .

This PR changes file uploading logic to buffer all files below 5mb in memory. This partially restoring previous behavior but avoiding full revert to s3.putObject API call which doesn't have retries.

Issue #, if available

#13681

Description of how you validated changes

PR checks and E2E tests.

Manual verification on t2.nano with sample test project where ENOMEM has been reproduced.

Checklist

• PR description included
• yarn test passes
• Tests are changed or added
• Relevant documentation is changed or added (and PR referenced)
• New AWS SDK calls or CloudFormation actions have been added to relevant test and service IAM policies
• Pull request labels are added

By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license.

[edwardfoyle]

Change LGTM. Did you also verify that uploading on a slow network still works as expected? See verification description in the previous PR: #13493 (comment)

[sobolk]

Change LGTM. Did you also verify that uploading on a slow network still works as expected? See verification description in the previous PR: #13493 (comment)

I played a bit with 3g profile, seems to be working.