Fix for retrieving ETag

[slitviachenko]

Description

For some reason (most likely an issue with the fragment variation creation API), the returned ETag is not always correct. It's better to directly retrieve the created variation and get the ETag from there. Additionally, I found that the created variation might not be instantly available after creation, so I added 1.5 seconds wait time.

Related Issue

https://jira.corp.adobe.com/browse/SITES-22574

Motivation and Context

How Has This Been Tested?

https://experience-qa.adobe.com/?devMode=true&shell_source=workspace&workspace=debuge1275950&shell_ims=prod&aemHost=author-p7452-e12437.adobeaemcloud.com&fragmentId=145d7832-8adc-47b7-b58d-778dc067861c#/@sitesinternal/aem/generate-variations/

Screenshots (if appropriate):

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)

Checklist:

• I have signed the Adobe Open Source CLA.
• My code follows the code style of this project.
• My change requires a change to the documentation.
• I have updated the documentation accordingly.
• I have read the CONTRIBUTING document.
• I have added tests to cover my changes.
• All new and existing tests passed.

[irenelagno]

@slitviachenko I'm ok with this solution as a workaround, but if we don't receive more complaints from the fields, I'd prefer to avoid delivering this fix and wait for a fix from the Sisi creak team. I found an issue really similar to the one we get: https://jira.corp.adobe.com/browse/SITES-22212. It's likely our use case is related to this one.

[irenelagno]

Need to keep in mind to check if we need to revert when https://jira.corp.adobe.com/browse/SITES-22212 is fixed

[slitviachenko]

@irenelagno , I have added you and me as watchers to https://jira.corp.adobe.com/browse/SITES-22212