The sum of all the local minimum values of the twice differentiable function \( f:\mathbb{R}\to\mathbb{R} \) defined by \( f(x)=x^{3}-3x^{2}-\dfrac{3\,f''(2)}{2}\,x+f'(1) \) is:
\( 5 \)
\( -22 \)
\( -27 \)
\( 0 \)