metrics.h --  remove unused MetricsPolicy   EnumerateFirstToLast
metrics.h --  remove unused MetricsPolicy   EnumerateFirstToLast

Signed-off-by: Ravi Varadarajan <7f1600b15de5bdc6ecd04b0bc7ba0a2de1f18226@ucsd.edu>

QuantamHD/OpenROAD,The-OpenROAD-Project/OpenROAD,QuantamHD/OpenROAD,The-OpenROAD-Project/OpenROAD,QuantamHD/OpenROAD,The-OpenROAD-Project/OpenROAD,QuantamHD/OpenROAD,The-OpenROAD-Project/OpenROAD,QuantamHD/OpenROAD,The-OpenROAD-Project/OpenROAD