The answer is no.
Sealing and destroying juvenile records is requested under Welfare & Institutions Code §§ 781 and 781.5. You referred to PC 851.7, which is close to 851.8. 851.8 is the penal code section under which one can ask a court, as an adult, for a declaration of factual innocence.
Speak to a Sacramento criminal defense attorney who has experience in juvenile matters.
My Sacramento office handles these on a regular basis for a very reasonable fee. Feel free to contact me by phone during business hours (8am-5pm) to discuss more fully.
If you have had no other adult conviction, and successfully completed the terms of your juvenile probation, then sealing your record is a smart move.
Thanks for writing.
Under 781 you are able to have your juvenile records sealed through a Petition to the Court, which is often handled through the probation department where there is a fee. These records include any arrests, and cases that were handled informally. In your situation, you should go to your Sheriff's department and get a Live Scan to see it if your citizen's arrest actually shows up on your record before you hire an attorney- if it does not (which sounds very plausible), you need not worry.