Fix scrolling in dialogs
Fix scrolling in dialogs

In change 350754 all dialog were changed to `overflow:visible` in order
to always have space to show hovercards inside dialogs, even if the
dialogs are too small.

But this new overflow style prevents scrolling. So we are removing it at
least temporarily.

Release-Notes: skip
Google-Bug-Id: b/258621585
Change-Id: I6780e39703d5e04df7627efa776b4ab3277c41f7

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