Move the SimpleParameters into LegacyProtoKey and rename it to LegacyProtoParametersNotForCreation.

This is useful in many contexts when one has a LegacyProtoKey. While one still cannot create a new key out of it, one can at least call toString() on the parameters object, which should be useful in other cases too.

Also this simplifies the constructor of a PrimitiveSet Entry.

PiperOrigin-RevId: 466319231
Change-Id: Iaf808da6f647414d34f35756158853f32add632c
4 files changed