Asserts on size_t >= 0

[jacob-moore22]

Our asserts need to be tweaked. With a verbose compiler I'm getting the following warning for most all of the asserts:

"<path>/kokkos_types.h", line 3834: warning: pointless comparison of unsigned integer with zero [unsigned_compare_with_zero]
      assert(j >= 0 && j < dims_[1] && "j is out of bounds in ViewCArrayKokkos 2D!");

Its a valid point, since j is a size_t, it is impossible for it to be anything other than >=0.