MM-14721 - Add an identifier for compliance exports when a message is posted by a bot account (#11063)

* check from_bot post property to override IsBot

model/message_export.go

@@ -23,6 +23,7 @@ type MessageExport struct {
 	PostMessage    *string
 	PostType       *string
 	PostRootId     *string
+	PostProps      *string
 	PostOriginalId *string
 	PostFileIds    StringArray
 }