Upgrade kotlin to 0.12.412

Bug: 21756156
diff --git a/databinding.properties b/databinding.properties
index effb03a..02460f9 100644
--- a/databinding.properties
+++ b/databinding.properties
@@ -1,5 +1,5 @@
 # global settings for projects
-kotlinVersion = 0.11.91
+kotlinVersion = 0.12.412
 version = 1.0-rc1-SNAPSHOT
 releaseVersion = 1.0-rc1-SNAPSHOT
 androidPluginVersion = 1.2.3