Update release SDK view text about changelog and date restrictions

Update SDK release view in management plane SDK release app to say:
> SDK must be released within 7 days of the date in CHANGELOG.md, and only after the SDK PR is merged. If delayed, update the date before triggering the release to avoid failures

Instead of:
> SDK release should be initiated after SDK PR is merged and within 7 days from the code generation date noted in changelog.md to prevent any failures. After 7 days, update the date in changelog.md.