Merge "camera2: Add some more docs to getConcurrentCameraIds" into rvc-dev am: d220792d

     * client camera application. Using these camera devices concurrently by two different

     * applications is not guaranteed to be supported, however.</p>

     *

     * <p>For concurrent operation, in chronological order :

     * - Applications must first close any open cameras that have sessions configured, using

     *   {@link CameraDevice#close}.

     * - All camera devices intended to be operated concurrently, must be opened using

     *   {@link #openCamera}, before configuring sessions on any of the camera devices.</p>

     *

     * <p>Each device in a combination, is guaranteed to support stream combinations which may be

     * obtained by querying {@link #getCameraCharacteristics} for the key

     * {@link android.hardware.camera2.CameraCharacteristics#SCALER_MANDATORY_CONCURRENT_STREAM_COMBINATIONS}.</p>

     *

     * <p>For concurrent operation, if a camera device has a non null zoom ratio range as specified

     * by

     * {@link android.hardware.camera2.CameraCharacteristics#CONTROL_ZOOM_RATIO_RANGE},

     * its complete zoom ratio range may not apply. Applications can use

     * {@link android.hardware.camera2.CaptureRequest#CONTROL_ZOOM_RATIO} >=1 and  <=

     * {@link android.hardware.camera2.CameraCharacteristics#SCALER_AVAILABLE_MAX_DIGITAL_ZOOM}

     * during concurrent operation.

     * <p>

     *

     * <p>The set of combinations may include camera devices that may be in use by other camera API

     * clients.</p>

     *