Set 42 days expiration time for Redis HLL metrics

What does this MR do?

Here we have defined known events, with some attributes https://gitlab.com/gitlab-org/gitlab/-/blob/master/lib/gitlab/usage_data_counters/known_events.yml the initial implementation had set 12 weeks, expiration time(84 days)

As the counters get data for the last 4 weeks I would say it could be enough to have 42 days

• Remove 84 days expiry from know_events.yml and use 42 days the default value
• Add more tests to check default expiry values
• Name events in tests for clarity

Screenshots

Does this MR meet the acceptance criteria?

Conformity

• Changelog entry
• Documentation (if required)
• Code review guidelines
• Merge request performance guidelines
• Style guides
• Database guides
• Separation of EE specific content

Availability and Testing

• Review and add/update tests for this feature/bug. Consider all test levels. See the Test Planning Process.
• Tested in all supported browsers
• Informed Infrastructure department of a default or new setting change, if applicable per definition of done

Security

If this MR contains changes to processing or storing of credentials or tokens, authorization and authentication methods and other items described in the security review guidelines:

• Label as security and @ mention @gitlab-com/gl-security/appsec
• The MR includes necessary changes to maintain consistency between UI, API, email, or other methods
• Security reports checked/validated by a reviewer from the AppSec team

Closes #239449 (closed)