Copy description from Cargo.toml to METADATA am: 1b5d2e302f

Original change: https://android-review.googlesource.com/c/platform/external/rust/crates/async-trait/+/1456776

Change-Id: Ib8c985b86c5a2a8a8bab03691de5fc3c9ed92f8b
diff --git a/METADATA b/METADATA
index 059a608..a0eb879 100644
--- a/METADATA
+++ b/METADATA
@@ -1,5 +1,5 @@
 name: "async-trait"
-description: "Async trait methods."
+description: "Type erasure for async trait methods"
 third_party {
   url {
     type: HOMEPAGE