Document face detection's new support for google talkback accessibility.

<p><b>Face detection</b> - If this is enabled, then the camera will automatically try to detect faces, and use

them for the focus, metering (exposure) and white balance. Faces will be drawn as yellow squares when detected.

Note that if this option is enabled, then you will not be able to touch to manually select the focus area, and

the white balance option will have no effect (since the face recognition will be used to determine these).</p>

the white balance option will have no effect (since the face recognition will be used to determine these). Also

note that if you are using an accessibility service such as Google Talkback, information about the number and

location of detected faces will be reported when face detection is enabled.</p>

<p><b>Timer</b> - Set a timer for taking photos or recording video. Press the take photo/video button again to

cancel the timer.</p>