Position tooltip in front of the dialog.
In order for the tooltip to be visible on the dialog it needs to be a
child of the dialog.
The change has a negative effect that the tooltip is now resized to not
overflow out of the dialog. Which I can't figure out an easy workaround
for at the moment.
Screenshot: https://imgur.com/a/FW2xpXn
Google-Bug-Id: b/306590615
Release-Notes: skip
Change-Id: I93ef83846599d58ba2b3d62836c5898325fa11f8
(cherry picked from commit bc7ccfef33f1a87c432134e7ec6d59e64ec085ba)
