Fix bug in getTemporaryIds()

[darrenfoong]

There is no need to multiply System.currentTimeMillis() by 1000 as it is already in milliseconds.

Also, it is better to use Instant, instead of performing accident-prone conversions (which appear often in the current code).

[achraf52]

I have verified that, as the name implies, calling System.currentTimeMillis(); returns the current timestamp in milliseconds, thus multiplication by 1000 will lead to erroneous values.