[iOS][MF] Enable pull to reset

Similar to pull to refresh, pulling the suggestions to the right will
reset the keyboard and the manual fallback view.

Video: https://drive.google.com/file/d/1QpoiU3YPXdFhLQ_ubzZcyJ7VxVo86Zpv/view?usp=sharing

Bug: 845472, 911142
Change-Id: Ie13322d168dac81288d95a8e10a0bcb5bab59339
Reviewed-on: https://chromium-review.googlesource.com/c/1355188
Commit-Queue: Javier Ernesto Flores Robles <javierrobles@chromium.org>
Reviewed-by: Olivier Robin <olivierrobin@chromium.org>
Reviewed-by: Brian White <bcwhite@chromium.org>
Cr-Original-Commit-Position: refs/heads/master@{#613169}(cherry picked from commit 30956fc7738fbebc7792e115520b5f58b719f752)
Reviewed-on: https://chromium-review.googlesource.com/c/1363197
Reviewed-by: Javier Ernesto Flores Robles <javierrobles@chromium.org>
Cr-Commit-Position: refs/branch-heads/3626@{#77}
Cr-Branched-From: d897fb137fbaaa9355c0c93124cc048824eb1e65-refs/heads/master@{#612437}
7 files changed