train info pull atom

Bug: 122807604
Test: will add gts
Change-Id: I2d6bdee1c5f17d5b2dc341a110605b6aaa6f4947

cmds/statsd/src/atoms.proto

@@ -296,6 +296,7 @@ message Atom {
         NumBiometricsEnrolled num_faces_enrolled = 10048;
         RoleHolder role_holder = 10049;
         DangerousPermissionState dangerous_permission_state = 10050;
+        TrainInfo train_info = 10051;
     }
 
     // DO NOT USE field numbers above 100,000 in AOSP.
@@ -5489,3 +5490,20 @@ message DeviceIdentifierAccessDenied {
     // True if the package is privileged.
     optional bool is_priv_app = 4;
 }
+
+/**
+ * Potential experiment ids that goes with a train install.
+ */
+message TrainExperimentIds {
+    repeated int64 experiment_id = 1;
+}
+
+/**
+ * Pulls the ongoing mainline install train version code.
+ * Pulled from StatsCompanionService
+ */
+message TrainInfo {
+    optional int64 train_version_code = 1;
+
+    optional TrainExperimentIds train_experiment_id = 2;
+}