Update Android.bp by running cargo_embargo

Test: ran cargo_embargo
Change-Id: I52ad78d6f5ac2af3c0c7d5978799e79784208df1
diff --git a/Android.bp b/Android.bp
index 03afc0d..54d2e17 100644
--- a/Android.bp
+++ b/Android.bp
@@ -45,7 +45,7 @@
     crate_name: "async_task",
     cargo_env_compat: true,
     cargo_pkg_version: "4.5.0",
-    srcs: ["src/lib.rs"],
+    crate_root: "src/lib.rs",
     edition: "2018",
     features: [
         "default",