Switched to `JsonSerializer` / `JsonDeserializer`

[demos/kafka/wordcount] / recorder

diff --git a/recorder b/recorder
index c5700c2..b06e664 160000 (submodule)
--- a/recorder
+++ b/recorder
@@ -1 +1 @@
-Subproject commit c5700c2117f6c445278f272572c8b5732bf53bbf
+Subproject commit b06e6649f54c4ab58cea812b96301dadbbd23b23