Refactor BottomSheetTest#testWrapContentHeightChange

Bug: 1334642
Change-Id: I674640e5315c9c380c650790cf21d5a3ea68b98a
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/4286549


Reviewed-by: Matthew Jones <mdjones@chromium.org>
Commit-Queue: Wolfgang Billenstein <bwolfgang@google.com>
Cr-Commit-Position: refs/heads/main@{#1108988}