Copy description from Cargo.toml to METADATA

Test: make
Change-Id: Ia8e99d94fbbf16627ae3882555321f7f7d36a1df
diff --git a/METADATA b/METADATA
index 2e5d655..eeb89e8 100644
--- a/METADATA
+++ b/METADATA
@@ -7,7 +7,7 @@
   }
   url {
     type: ARCHIVE
-    value: "https://static.crates.io/crates/smallvec/smallvec-1.4.1.crate"
+    value: "https://static.crates.io/crates/smallvec/smallvec-1.4.2.crate"
   }
   version: "1.4.2"
   license_type: NOTICE