Revert of Set camera parameters continuous focus mode on (patchset #1 id:1 of https...

Revert of Set camera parameters continuous focus mode on (patchset #1 id:1 of https://codereview.chromium.org/737003003/)

Reason for revert:
Looks like this is causing MANUAL_CanAcquireVgaOnRealWebcam to fail.

Original issue's description:
> Android Video Capture: Set continuous focus mode on in cam parameters.
>
> This is, apparently, needed for macro modes, although
> autofocus seems to work ok in general.
>
> BUG=343894
> TEST=Please refer to the bug, basically a gUM() + close QR codes focus test.
>
> Committed: https://crrev.com/667e79783dd2bbd413b165abfd7fae2bfa3210d5
> Cr-Commit-Position: refs/heads/master@{#304909}

TBR=qinmin@chromium.org,mcasas@chromium.org
NOTREECHECKS=true
NOTRY=true
BUG=343894

Review URL: https://codereview.chromium.org/740363002

Cr-Commit-Position: refs/heads/master@{#305009}