Prior to this commit, all 2xx HTTP responses were eligible for ETag
generation in ShallowEtagHeaderFilter. In some cases, this would use
CPU resources for no reason since HTTP clients would not use ETags.
This commit is an optimization and restricts ETags generation in cases
where (all conditions must be met):
- response has a 2xx status
- request is a GET
- response does not contain "no-store" in its "Cache-Control" header
Issue: SPR-11110
6fba8292f5