[IOS][LO] Expand the entrypoint's tap target size

This CL updates the width of the entrypoint to expand its tap target
size to be 44.
It also removes the leading constraint as it is no longer needed now
that the width is increased.

Bug: 374254373
Change-Id: Ia0043f52484e7319b6b3713b39b856eebee191d9
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5941350


Reviewed-by: Stepan Khapugin <stkhapugin@chromium.org>
Commit-Queue: Ameur Hosni <ameurhosni@google.com>
Cr-Commit-Position: refs/heads/main@{#1370684}