docs: correct stated defaults in Chroma pipeline docstrings (#14578)

Seven `defaults to X` entries in the three Chroma pipelines' __call__
docstrings name a value the signature does not use, so copying the
documented number reproduces different behavior than leaving the argument
out. Values taken from each __call__ signature.

Co-authored-by: Claude Opus 5 (1M context) <noreply@anthropic.com>