Update Android.bp by running cargo_embargo am: 47a539c554

Original change: https://android-review.googlesource.com/c/platform/external/rust/crates/maybe-async/+/3079316

Change-Id: Ib97fd7a0d335d5de73486973d5124c4cb33757c8
Signed-off-by: Automerger Merge Worker <[email protected]>
diff --git a/Android.bp b/Android.bp
index e650a51..c9aa07f 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.
 
 // TODO: Add license.
 rust_proc_macro {