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.

Review URL: https://codereview.chromium.org/737003003

Cr-Commit-Position: refs/heads/master@{#304909}
1 file changed