Log information for Mixed Builds modules.
Test: Output matches expected. https://paste.googleplex.com/5913495636803584?raw
Performance evaluated: https://docs.google.com/spreadsheets/d/1X7eOVBKEZUwUWl5i8CDfBo9yUeZrDPXWi2JYO4BEZt4/edit?resourcekey=0-co8crIFW9dpiedhCMkhAgw#gid=0

Change-Id: I88780c7cc52a189a72216c5e2e499c96574b3731
diff --git a/android/metrics.go b/android/metrics.go
index 9038bde..1580f82 100644
--- a/android/metrics.go
+++ b/android/metrics.go
@@ -17,6 +17,7 @@
 import (
 	"io/ioutil"
 	"runtime"
+	"sort"
 
 	"github.com/google/blueprint/metrics"
 	"google.golang.org/protobuf/proto"
@@ -78,6 +79,23 @@
 		}
 		metrics.Events = append(metrics.Events, &perfInfo)
 	}
+	mixedBuildsInfo := soong_metrics_proto.MixedBuildsInfo{}
+	mixedBuildEnabledModules := make([]string, 0, len(config.mixedBuildEnabledModules))
+	for module, _ := range config.mixedBuildEnabledModules {
+		mixedBuildEnabledModules = append(mixedBuildEnabledModules, module)
+	}
+
+	mixedBuildDisabledModules := make([]string, 0, len(config.mixedBuildDisabledModules))
+	for module, _ := range config.mixedBuildDisabledModules {
+		mixedBuildDisabledModules = append(mixedBuildDisabledModules, module)
+	}
+	// Sorted for deterministic output.
+	sort.Strings(mixedBuildEnabledModules)
+	sort.Strings(mixedBuildDisabledModules)
+
+	mixedBuildsInfo.MixedBuildEnabledModules = mixedBuildEnabledModules
+	mixedBuildsInfo.MixedBuildDisabledModules = mixedBuildDisabledModules
+	metrics.MixedBuildsInfo = &mixedBuildsInfo
 
 	return metrics
 }