Fix version in METADATA

So that tools/external_updater can check updates for this library.

Exempt-From-Owner-Approval: No code change
Test: NA
Change-Id: Iee1179c7e5ed625c798965360a980bbd02d2625d
diff --git a/METADATA b/METADATA
index 3d5fab2..ff1fa49 100644
--- a/METADATA
+++ b/METADATA
@@ -11,7 +11,7 @@
     type: GIT
     value: "https://github.com/square/javapoet.git"
   }
-  version: "1.11.1"
+  version: "javapoet-1.11.1"
   last_upgrade_date { year: 2018 month: 11 day: 19 }
 }