[iOS][MF] Add more spacing on iPads

The space was modifidied in order to match Apple's next and previous
arrows below them.

Bug: 912551
Change-Id: I41955034a9b9af396ef710dbb494d5a97bbc799f
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1505946
Commit-Queue: Javier Ernesto Flores Robles <javierrobles@chromium.org>
Reviewed-by: Olivier Robin <olivierrobin@chromium.org>
Cr-Commit-Position: refs/heads/master@{#638251}
1 file changed