Potential issue on @timestamp formats

[lucasponce]

According to the template description:
https://github.com/ViaQ/elasticsearch-templates/blob/master/namespaces/_default_.yml#L17
The @timestamp field is parsed from a string with a possible pattern as
"yyyy-MM-dd'T'HH:mm:ss.SSSSSSZ"
Working in the integration plugins for Hawkular I realized about a potential problem on this.
For example:
"2017-04-03T18:05:35.415123+0200"
The field 415123 would be considered in Java as 415 seconds and 123 milliseconds with the pattern SSSSSSZ instead of 415 milliseconds and 123 nanoseconds as I think it should be parsed.
I am fixing this on Hawkular Alerting plugins but just leaving a note here as this potencial issue happens without hitting any exception (as the parsed is correct but with wrong calculation), but once I looked in detail I realized there was some unexpected drifts on the timestamps.

I haven't investigated if Elasticsearch is also affected by this.