Similar to [CustomTimestampPolicyWithLimitedDelay](https://github.com/apache/beam/blob/243128a8fc52798e1b58b0cf1a271d95ee7aa241/sdks/java/io/kafka/src/main/java/org/apache/beam/sdk/io/kafka/CustomTimestampPolicyWithLimitedDelay.java) in KafkaIO, JmsIO can consider adding the same functionality to allow configuring timestamp policy. Imported from Jira [BEAM-12336](https://issues.apache.org/jira/browse/BEAM-12336). Original Jira may contain additional context. Reported by: boyuanz.