[IOS][AIM] Use shared aim shortcut flag

Use the shared aim shortcut flag, as it will be used to add shared
logic in components code.

Change-Id: I7bd101285eb26a8b4048431261e8d1819b8434a9
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/6790652
Commit-Queue: Ameur Hosni <ameurhosni@google.com>
Reviewed-by: Stepan Khapugin <stkhapugin@chromium.org>
Auto-Submit: Ameur Hosni <ameurhosni@google.com>
Commit-Queue: Stepan Khapugin <stkhapugin@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1492698}