Reland "[iOS] Fix Add to Group in TabGrid selection"

This is a reland of commit 9a550abf

Original change's description:
> [iOS] Fix Add to Group in TabGrid selection
>
> If shareable and non-sharable tabs are selected, they should all be
> movable to new or existing tab group using the selection mode in the
> TabGrid.
>
> Fixed: 331745630, 328425613
> Change-Id: Ia9277351e4a3530b67f0fe95facf14876fa5ec05
> Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5401801


> Auto-Submit: Gauthier Ambard <gambard@chromium.org>
> Reviewed-by: Louis Romero <lpromero@google.com>
> Commit-Queue: Gauthier Ambard <gambard@chromium.org>
> Cr-Commit-Position: refs/heads/main@{#1280134}

Change-Id: Iae24b14d79602e4a217056d2f240e9c3db0803cf
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5407332


Commit-Queue: Aliona Dangla <alionadangla@chromium.org>
Commit-Queue: Gauthier Ambard <gambard@chromium.org>
Reviewed-by: Aliona Dangla <alionadangla@chromium.org>
Auto-Submit: Gauthier Ambard <gambard@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1280159}