Add comment about disable VUR if property is large.

     * This applies for continuous property only.

     *

     * It is HIGHLY RECOMMENDED to support variable update rate for all non-heartbeat continuous

     * properties for better performance.

     * properties for better performance unless the property is large.

     *

     * If variable update rate is supported and 'enableVariableUpdateRate' is true in subscribe

     * options, VHAL must only sends property update event when the property's value changes

     * property event, and must use getValues to fetch the initial value. In fact, car service is

     * using getValues to fetch the initial value, convert it to a property event and deliver to

     * car service clients.

     *

     * NOTE: If this is true, car service may cache the property update event for filtering purpose,

     * so this should be false if the property is large (e.g. a byte array of 1k in size).

     */

    boolean supportVariableUpdateRate;

}