Clarify managed identities permissions and role membership cache verbiage in overview-managed-identity.md.

[EvanSchallerer]

Update overview-managed-identity.md to describe the caching behavior of managed identity role memberships and permissions more clearly. The previous language misused the word "several" to refer to values up to 24, which is confusing.

[prmerger-automator[bot]]

@EvanSchallerer : Thanks for your contribution! The author(s) and reviewer(s) have been notified to review your proposed change.

[v-dirichards]

@cephalin

Can you review the proposed changes?

Important: When the changes are ready for publication, adding a #sign-off comment is the best way to signal that the PR is ready for the review team to merge.

#label:"aq-pr-triaged" @MicrosoftDocs/public-repo-pr-review-team

[v-dirichards]

@cephalin Could you review this proposed update to your article and enter #sign-off in a comment if it's ready to merge?

Thanks!

[v-dirichards]

@cephalin

Can you review this old PR and determine whether it needs to be closed or merged?

@MicrosoftDocs/public-repo-pr-review-team

[ttorble]

I sent email to the content owner today.

@MicrosoftDocs/public-repo-pr-review-team

[v-dirichards]

I sent a Teams message to the content owner today.

@MicrosoftDocs/public-repo-pr-review-team

[cephalin]

#sign-off