AppEngine: Milliseconds are dropped from query parameters

[Annopaolo]

I published some data on interface com.samples.Example with device 2Qcgg5oKQJWOzVXrKnUsNg.

$ curl -X GET http://localhost:4002/v1/test/devices/2Qcgg5oKQJWOzVXrKnUsNg/interfaces/com.samples.GPS -H  "accept: */*" -H  "Authorization: Bearer $JWT"
{"data":{"sensors":{"gps":[{"timestamp":"2021-10-06T14:12:50.722Z","x":43.0,"y":11.0,"z":3.0},{"timestamp":"2021-10-06T14:13:20.320Z","x":45.0,"y":12.0,"z":3.0},{"timestamp":"2021-10-06T14:13:51.403Z","x":45.0,"y":12.0,"z":3.0}]}}}

When, for example, I try to retrieve the last one using a since param, I get the following:

$ curl -X GET http://localhost:4002/v1/test/devices/2Qcgg5oKQJWOzVXrKnUsNg/interfaces/com.samples.GPS?since=2021-10-06T14:13:51.403Z -H  "accept: */*" -H  "Authorization: Bearer $JWT"
{"data":{"sensors":{"gps":[{"timestamp":"2021-10-06T14:13:51.403Z","x":45.0,"y":12.0,"z":3.0}]}}}

Then, if I change the milliseconds value in the query 403Z to 999Z, I still get the same result:

$ curl -X GET http://localhost:4002/v1/test/devices/2Qcgg5oKQJWOzVXrKnUsNg/interfaces/com.samples.GPS?since=2021-10-06T14:13:51.999Z -H  "accept: */*" -H  "Authorization: Bearer $JWT"
{"data":{"sensors":{"gps":[{"timestamp":"2021-10-06T14:13:51.403Z","x":45.0,"y":12.0,"z":3.0}]}}}

Which is obviously wrong, because the message was sent before the since value.
If I change the seconds value instead, the query correctly returns no data.
I suspect milli/microseconds values are dropped from the query.
This might relate to #553.

[Annopaolo]

Closed by #621.