Cal. Probate Code - PROB § 7220. Section 7220.
In proceedings under this code concerning the administration of the decedent’s estate, a motion for a new trial may be made only in the following cases:
(a)
Contest of a will or revocation of probate of a will.
(b)
Cases in which a right to jury trial is expressly granted, whether or not the case was tried by a jury.