Camera2: Update sceneFlicker tag spec

            new Key<Rational[]>("android.statistics.predictedColorTransform", Rational[].class);

    /**

     * <p>The HAL estimated scene illumination lighting

     * frequency</p>

     * <p>Report NONE if there doesn't appear to be flickering

     * illumination</p>

     * <p>The camera device estimated scene illumination lighting

     * frequency.</p>

     * <p>Many light sources, such as most fluorescent lights, flicker at a rate

     * that depends on the local utility power standards. This flicker must be

     * accounted for by auto-exposure routines to avoid artifacts in captured images.

     * The camera device uses this entry to tell the application what the scene

     * illuminant frequency is.</p>

     * <p>When manual exposure control is enabled

     * (<code>{@link CaptureRequest#CONTROL_AE_MODE android.control.aeMode} == OFF</code> or <code>{@link CaptureRequest#CONTROL_MODE android.control.mode} == OFF</code>),

     * the {@link CaptureRequest#CONTROL_AE_ANTIBANDING_MODE android.control.aeAntibandingMode} doesn't do the antibanding, and the

     * application can ensure it selects exposure times that do not cause banding

     * issues by looking into this metadata field. See android.control.aeAntibandingMode

     * for more details.</p>

     * <p>Report NONE if there doesn't appear to be flickering illumination.</p>

     *

     * @see CaptureRequest#CONTROL_AE_ANTIBANDING_MODE

     * @see CaptureRequest#CONTROL_AE_MODE

     * @see CaptureRequest#CONTROL_MODE

     * @see #STATISTICS_SCENE_FLICKER_NONE

     * @see #STATISTICS_SCENE_FLICKER_50HZ

     * @see #STATISTICS_SCENE_FLICKER_60HZ