The AsArrayTypeDeserializer causes date values to be rendered as an array like [java.util.Date, 1561543964015] an therefore is 1. skipped when flattening and 2. if not skipped cannot be read back.
We now register an error handler along with a custom deserializer aware of the used date format to write and read date values without having to store an array but just the date msec.
Original pull request: #467.
a2831bef84