run_train: pass save_predictions flag through like enable_reporterv2 (#30)

Author: utkarshgill

run_train.sh

@@ -48,6 +48,7 @@ for arg in "$@"; do
     master_addr=*) MASTER_ADDR="${arg#master_addr=}" ;;
     master_port=*) MASTER_PORT="${arg#master_port=}" ;;
     --metrics.enable_reporterv2=) TORCHTITAN_ARGS+=("--metrics.enable_reporterv2") ;;
+    --validator.save_predictions=) TORCHTITAN_ARGS+=("--validator.save_predictions") ;;
     *) TORCHTITAN_ARGS+=("$arg") ;;
   esac
 done