Update Android.bp by running cargo_embargo

Test: ran cargo_embargo
Change-Id: Ica6099e65b46ba670962ba529208ef2022683d6b
diff --git a/Android.bp b/Android.bp
index 2713e65..7cef1e5 100644
--- a/Android.bp
+++ b/Android.bp
@@ -28,7 +28,7 @@
     crate_name: "plotters_backend",
     cargo_env_compat: true,
     cargo_pkg_version: "0.3.5",
-    srcs: ["src/lib.rs"],
+    crate_root: "src/lib.rs",
     edition: "2018",
     apex_available: [
         "//apex_available:platform",