That was part of it:

Payne’s Special Conditions of Parole included a more detailed condition (“special search condition”) concerning electronic devices: You shall surrender any digital/electronic device and provide a pass key/code to unlock the device to any law enforcement officer for inspection other than what is visible on the display screen. This includes any digital/electronic device in your vicinity. Failure to comply can result in your arrest pending further investigation and/or confiscation of any device pending investigation.

He refused, which did violate his parole.

At this juncture, CHP officers would have been justified under Payne’s special search condition in either “confiscati[ng] . . . [the] device” or “arrest[ing] Payne pending further investigation.

Instead, Officer Coddington forcibly grabbed Payne’s thumb and used it to unlock the phone via a built-in biometric unlocking feature.

It's the last bit that is the important part. That is not part of the conditions of the parole. And that is what the court found was not a rights violation.