Upgrade async-trait to 0.1.73

This project was upgraded with external_updater.
Usage: tools/external_updater/updater.sh update rust/crates/async-trait
For more info, check https://cs.android.com/android/platform/superproject/+/main:tools/external_updater/README.md

Test: TreeHugger
Change-Id: I6ca2d54e5684edb52f2cf797d4a7ddb1727a3b02
Bug: 295883071
diff --git a/Android.bp b/Android.bp
index 0ded84e..29d4efd 100644
--- a/Android.bp
+++ b/Android.bp
@@ -41,9 +41,9 @@
     name: "libasync_trait",
     crate_name: "async_trait",
     cargo_env_compat: true,
-    cargo_pkg_version: "0.1.67",
+    cargo_pkg_version: "0.1.73",
     srcs: ["src/lib.rs"],
-    edition: "2018",
+    edition: "2021",
     rustlibs: [
         "libproc_macro2",
         "libquote",