Update Android.bp by running cargo_embargo

Test: ran cargo_embargo
Change-Id: Ifaf01842aae352ee0edd25a3b3f42919a4b01c02
diff --git a/Android.bp b/Android.bp
index 59943e8..1d34b10 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: ["external_rust_crates_futures-macro_license"],