[ci skip][docs]Fix Active Support changelog (7.1 beta1)

[hachi8833]

Motivation / Background

I found some small errors on Active Support changelog.

Detail

This Pull Request fixes:

• args on sample assert_equal
• add missing html_safe?

Checklist

Before submitting the PR make sure the following are checked:

• This Pull Request is related to one change. Changes that are unrelated should be opened in separate PRs.
• Commit message has a detailed description of what changed and why. If this PR fixes a related issue include it in the commit message. Ex: [Fix #issue-number]
• CHANGELOG files are updated for the changed libraries if there is a behavior change or additional feature. Minor bug fixes and documentation changes should not be included.