Import protobuf-codegen-2.14.0

* Add OWNERS, Android.bp, and README.android.
* Hard code version number in src/lib.rs for now.
  It could be in a smarter update_package.sh to get the
  new version number from Cargo.tom. But until then,
  the difference in lib.rs will be caught and fixed manually.
* Rename protoc_gen_rust to protoc-gen-rust for aprotoc plugin.

Bug: 143953733
Test: make
Change-Id: I9b3c3b9f2e7ad0eb203c26534f2b6ba5fac46eef
diff --git a/src/syntax.rs b/src/syntax.rs
new file mode 100644
index 0000000..d075063
--- /dev/null
+++ b/src/syntax.rs
@@ -0,0 +1,15 @@
+#[derive(Debug, Copy, Clone, PartialEq, Eq)]
+pub enum Syntax {
+    PROTO2,
+    PROTO3,
+}
+
+impl Syntax {
+    pub fn parse(s: &str) -> Self {
+        match s {
+            "" | "proto2" => Syntax::PROTO2,
+            "proto3" => Syntax::PROTO3,
+            _ => panic!("unsupported syntax value: {:?}", s),
+        }
+    }
+}