E2E: Increase wait duration for group import validation

What does this MR do?

Increase wait time for group import.

Unfortunately performance improvement (#332351) currently is very low in priority list (there is an internal logic which reports status in 1 minute increments which is bad for tests of small project imports).

This change should not affect most of the runs as import mostly finishes sooner, but hopefully should reduce failures on staging.

Closes: #332721 (closed)