Update Android.bp by running cargo_embargo

Test: ran cargo_embargo
Change-Id: I4c594a2066cfbbe68f8c9b3e77228c76826bc777

Android.bp

diff --git a/Android.bp b/Android.bp
index 2137241..8432cf4 100644
--- a/Android.bp
+++ b/Android.bp
@@ -1,5 +1,7 @@
 // This file is generated by cargo_embargo.
-// Do not modify this file as changes will be overridden on upgrade.
+// Do not modify this file after the first "rust_*" or "genrule" module
+// because the changes will be overridden on upgrade.
+// Content before the first "rust_*" or "genrule" module is preserved.
 
 package {
     default_applicable_licenses: [
@@ -25,7 +27,7 @@
     crate_name: "tracing_attributes",
     cargo_env_compat: true,
     cargo_pkg_version: "0.1.27",
-    srcs: ["src/lib.rs"],
+    crate_root: "src/lib.rs",
     edition: "2018",
     rustlibs: [
         "libproc_macro2",