Fix comment metadata disappearing for comments with no children

[micahmo]

Pull Request Description

This PR fixes a small regression from #1890 where metadata from comments with no children would get hidden when tapped, even though there was no child comment count to take its place.

Issue Being Fixed

Issue Number: N/A

Screenshots / Recordings

Before

qemu-system-x86_64_PDMdayXVod.mp4

After

qemu-system-x86_64_eDB0F69IIX.mp4

Checklist

• If a new package was added, did you ensure it uses an appropriate license and is actively maintained?
• Did you use localized strings (and added appropriate descriptions) where applicable?
• Did you add semanticLabels where applicable for accessibility?

[hjiangsu]

LGTM!