codec2: add a constructor of C2FieldSupportedValues w/ input vector

In V4L2 case, some parameters (ex. supported profiles) would be a set of
numbers which queries from V4L2 driver. We couldn't determine it before runtime
so we couldn't use initializer_list.

Test: run C2Param_test

Change-Id: Ia89076ba7245d8a9cbe855a1a2646a05d7aa1656