Unless a contrary intent clearly appears elsewhere in this title, any right granted to a child by this title or by the constitution or laws of this state or the United States may be waived in proceedings under this title if:
(1) the waiver is made by the child and the attorney for the child;
(2) the child and the attorney waiving the right are informed of and understand the right and the possible consequences of waiving it;
(3) the waiver is voluntary; and
(4) the waiver is made in writing or in court proceedings that are recorded.