Codec2: remove unneeded const from query/commit methods

const std::vector<C2Param *> already enforces const pointer members
(C2Param *const). However, it is nearly impossible to construct
a vector of const pointer values as they are not resizable.

Bug: 64121714
Change-Id: If8bbf0e4da522a26d8dc64e3c9e507b5c4b36dab