Add setup_tools performance metrics to Soong protobuf file.

The setup_tools metrics has been missing since day one and is
needed to track down slowness of setting up the build system.

Bug: b/175706305
Test: m nothing and ran the printproto command to check that the
      setup_tools field has been set.
Change-Id: Idc8a38fa830e0a906170feeede63435715eaa05b

ui/metrics/metrics.go

@@ -60,6 +60,8 @@ func (m *Metrics) SetTimeMetrics(perf soong_metrics_proto.PerfInfo) {
 		m.metrics.BazelRuns = append(m.metrics.BazelRuns, &perf)
 	case PrimaryNinja:
 		m.metrics.NinjaRuns = append(m.metrics.NinjaRuns, &perf)
+	case RunSetupTool:
+		m.metrics.SetupTools = append(m.metrics.SetupTools, &perf)
 	case Total:
 		m.metrics.Total = &perf
 	}