Update protobuf to 2.27.1

Test: cd external/rust/crates && atest --host -c
Change-Id: Iaae5fc30f1bd87b2d4a92ee1ae07bc18e1bc50d4
diff --git a/src/plugin.rs b/src/plugin.rs
index 77e1666..93f2ca8 100644
--- a/src/plugin.rs
+++ b/src/plugin.rs
@@ -1,4 +1,4 @@
-// This file is generated by rust-protobuf 2.22.0. Do not edit
+// This file is generated by rust-protobuf 2.26.0. Do not edit
 // @generated
 
 // https://github.com/rust-lang/rust-clippy/issues/702