Update Android.bp by running cargo_embargo am: 646e970552 am: a7214bbf52

Original change: https://android-review.googlesource.com/c/platform/external/rust/crates/threadpool/+/3095964

Change-Id: I16becc821228e5d4b415927981378251621cd603
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>

Android.bp

diff --git a/Android.bp b/Android.bp
index ef95523..f2c585d 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_threadpool_license"],
@@ -24,7 +26,7 @@
     crate_name: "threadpool",
     cargo_env_compat: true,
     cargo_pkg_version: "1.8.1",
-    srcs: ["src/lib.rs"],
+    crate_root: "src/lib.rs",
     edition: "2015",
     rustlibs: ["libnum_cpus"],
     apex_available: [