rust: Support protobuf wrappers well known types

Test: m nothing

Change-Id: I271474f59745670cbba98704182d0966eae6b0ee
diff --git a/rust/protobuf.go b/rust/protobuf.go
index b91fea8..9fe27c4c 100644
--- a/rust/protobuf.go
+++ b/rust/protobuf.go
@@ -188,6 +188,12 @@
 			lines,
 			"pub mod empty {",
 			"    pub use protobuf::well_known_types::Empty;",
+			"}",
+			"pub mod wrappers {",
+			"    pub use protobuf::well_known_types::{",
+			"        DoubleValue, FloatValue, Int64Value, UInt64Value, Int32Value, UInt32Value,",
+			"        BoolValue, StringValue, BytesValue",
+			"    };",
 			"}")
 	}