Update Android.bp by running cargo_embargo

Test: ran cargo_embargo
Change-Id: Ide23290c46f7617552fa50157a27d4d0c6c04e52
diff --git a/Android.bp b/Android.bp
index c289694..9c164eb 100644
--- a/Android.bp
+++ b/Android.bp
@@ -45,7 +45,7 @@
     crate_name: "cexpr",
     cargo_env_compat: true,
     cargo_pkg_version: "0.6.0",
-    srcs: ["src/lib.rs"],
+    crate_root: "src/lib.rs",
     edition: "2018",
     rustlibs: ["libnom"],
     apex_available: [