fix: Polymer packet decoding

Author: jsanmigimeno

src/collector/polymer/polymer.service.ts

@@ -163,11 +163,11 @@ const bootstrap = async () => {
 
           // Derive the message identifier
           const amb: AmbMessage = {
-            messageIdentifier: '0x' + packet[3].slice(1 * 2, 1 * 2 + 32 * 2),
+            messageIdentifier: '0x' + params[3].slice(1 * 2, 1 * 2 + 32 * 2),
             amb: 'polymer',
             sourceChain: chainId,
             destinationChain,
-            payload: packet[3],
+            payload: params[3],
           };
 
           // Set the collect message  on-chain. This is not the proof but the raw message.