common: added drive_state proto for engagement advice

modules/common/proto/BUILD

@@ -147,3 +147,17 @@ proto_library(
         "//modules/localization/proto:pose_proto_lib",
     ],
 )
+
+proto_library(
+    name = "drive_state_proto_lib",
+    srcs = [
+        "drive_state.proto",
+    ],
+)
+
+cc_proto_library(
+    name = "drive_state_proto",
+    deps = [
+        ":drive_state_proto_lib",
+    ],
+)

modules/common/proto/drive_state.proto

+syntax = "proto2";
+
+package apollo.common;
+
+
+// This is the engage advice that published by critical runtime modules.
+message EngageAdvice {
+    enum Advice {
+        UNKNOWN = 0;
+        DISALLOW_ENGAGE = 1;
+        READY_TO_ENGAGE = 2;
+        KEEP_ENGAGED = 3;
+        PREPARE_DISENGAGE = 4;
+    }
+
+    optional Advice advice = 1 [default = DISALLOW_ENGAGE];
+    optional string reason = 2;
+}