Update Android.bp by running cargo_embargo

Test: ran cargo_embargo
Change-Id: I80042eee2c77211225b07ec1516bbf85f3993c26
diff --git a/Android.bp b/Android.bp
index 5dd5f87..63ef59a 100644
--- a/Android.bp
+++ b/Android.bp
@@ -26,7 +26,7 @@
     crate_name: "grpcio",
     cargo_env_compat: true,
     cargo_pkg_version: "0.13.0",
-    srcs: ["src/lib.rs"],
+    crate_root: "src/lib.rs",
     edition: "2018",
     features: [
         "_secure",