Camera: improve session.close documentation

     * <p>Closing a session frees up the target output Surfaces of the session for reuse with either

     * a new session, or to other APIs that can draw to Surfaces.</p>

     *

     * <p>Note that creating a new capture session with {@link CameraDevice#createCaptureSession}

     * <p>Note that for common usage scenarios like creating a new session or closing the camera

     * device, it is faster to call respective APIs directly (see below for more details) without

     * calling into this method. This API is only useful when application wants to uncofigure the

     * camera but keep the device open for later use.</p>

     *

     * <p>Creating a new capture session with {@link CameraDevice#createCaptureSession}

     * will close any existing capture session automatically, and call the older session listener's

     * {@link StateCallback#onClosed} callback. Using {@link CameraDevice#createCaptureSession}

     * directly without closing is the recommended approach for quickly switching to a new session,

     * since unchanged target outputs can be reused more efficiently.</p>

     *

     * <p>Closing the device with {@link CameraDevice#close} directly without calling this API is

     * also recommended for quickly closing the camera.</p>

     *

     * <p>Once a session is closed, all methods on it will throw an IllegalStateException, and any

     * repeating requests or bursts are stopped (as if {@link #stopRepeating()} was called).

     * However, any in-progress capture requests submitted to the session will be completed as