Nope.
As this source says, there has only been one Oshawott event (which is where all Cherish Balls come from), and that event did not have Oshawott in a Cherish Ball, it was a Hisuian Poké Ball. Since Cherish Balls cannot be inherited through breeding nor obtained legitimately, an Oshawott with a Cherish Ball is unobtainable apart from events which have not occurred.
Hope I helped!
