I doubt that very very much.
California doesn't really produce anything but luxury produce and specialty items.
It doesn't produce the "meat & potatoes," that the nation eats. It produces the masses of specialty crops, and the large variety of fruits and veggies.
Anyone that has driven across country knows, the REAL farmers are in the upper & lower mid-west. The potatoes are out in Idaho. The dairy is elsewhere. . . certainty you folks aren't necessary for our pork, chickens, beef or dairy. We don't need you for corn, wheat, beans. . . etc. All you do is fruits and veggies.
As far as the specialty crops? We would still have a lot from Mexico, and the Great Lakes basin, along with N. England would pick up the slack, along with Iberia.
Of course, prices would take a hit, but we would get along fine with out ya.
Starve? Hell no.
Don't over estimate your importance. If you weren't so busy stealing water from surrounding states, you wouldn't be able to grow shit.