Revert "[Duet] Disable adaptive toolbar when GTS is enabled."

This reverts commit 4cc35386d5dc392cc8d0e9b5628e5fbda0748ba3.

Reason for revert: Causing crashes: https://bugs.chromium.org/p/chromium/issues/detail?id=947202#c1

Original change's description:
> [Duet] Disable adaptive toolbar when GTS is enabled.
>
> Disable apative toolbar when the grid tab switcher is enabled. Also
> don't enable adaptive toolbar if the bottom toolbar is not enabled.
>
> Bug: 944653
> Change-Id: I0c6e7319dc130def60103286452f3fccd5e6ac48
> Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1536297
> Reviewed-by: Yusuf Ozuysal <yusufo@chromium.org>
> Commit-Queue: Pedro Amaral <amaralp@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#644430}

TBR=yusufo@chromium.org,amaralp@chromium.org

# Not skipping CQ checks because original CL landed > 1 day ago.

Bug: 944653
Change-Id: Ib046de481f58ff412a73602cc4a045f95a1369fc
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1544821
Commit-Queue: Pedro Amaral <amaralp@chromium.org>
Reviewed-by: Pedro Amaral <amaralp@chromium.org>
Cr-Commit-Position: refs/heads/master@{#645535}