Revert "Disable DriveFS by default."

This reverts commit a077ed270f9d4b0ee266bd3cac8ce7ea7f1d408c.

Reason for revert: Just for merging to 73.

Original change's description:
> Disable DriveFS by default.
> 
> Bug: 819822
> Change-Id: I84722e0281f6db18a4a347fee9914fc34ebb8825
> Reviewed-on: https://chromium-review.googlesource.com/c/1475560
> Reviewed-by: Sergei Datsenko <dats@chromium.org>
> Commit-Queue: Sam McNally <sammc@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#633023}

TBR=sammc@chromium.org,dats@chromium.org

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

Bug: 819822
Change-Id: I2e7eb47359ca2b7a65356957914872d4e4d7acfe
Reviewed-on: https://chromium-review.googlesource.com/c/1476945
Reviewed-by: Sam McNally <sammc@chromium.org>
Commit-Queue: Sam McNally <sammc@chromium.org>
Cr-Commit-Position: refs/heads/master@{#633204}
1 file changed