Android video capture: Set camera parameters continuous focus mode on, where supported

This is, apparently, needed for macro modes, although autofocus seems to
work ok in general.

A similar CL was landed and reverted (http://crrev.com/737003003). This CL
is an alternative where the supported focus modes are tested before being
set in the Camera.Parameters.

BUG=343894
TEST=Please refer to the bug, basically a gUM() + close text or QR codes focus test.

Review URL: https://codereview.chromium.org/744193002

Cr-Commit-Position: refs/heads/master@{#305117}
1 file changed