Upgrade rust/crates/protobuf to 2.17.0

* Android.bp was regenerated. New rustc warnings were found.
* Keep local change in src/lib.rs to include out/version.rs.
* Update out/version.rs to the new version.

Change-Id: I9c2f7d412dcd42fe3769505629e05ab949300fe6
Test: make
diff --git a/Android.bp b/Android.bp
index 013d698..0cd68bf 100644
--- a/Android.bp
+++ b/Android.bp
@@ -2,10 +2,11 @@
 
 rust_library {
     name: "libprotobuf",
+    // has rustc warnings
     host_supported: true,
     crate_name: "protobuf",
     srcs: ["src/lib.rs"],
-    edition: "2015",
+    edition: "2018",
     features: [
         "bytes",
     ],