twister: Fix ram/rom reporting

The info of rom/ram usage by an application was lost along the
way of data processing in twister. The commit add a line which
pass further these metrices as well.

Signed-off-by: Maciej Perkowski <Maciej.Perkowski@nordicsemi.no>

scripts/twister

@@ -1215,6 +1215,7 @@ def main():
             except queue.Empty:
                 break
             else:
+                inst.metrics.update(suite.instances[inst.name].metrics)
                 inst.metrics["handler_time"] = inst.handler.duration if inst.handler else 0
                 inst.metrics["unrecognized"] = []
                 suite.instances[inst.name] = inst