Fixes #480 - Increase the timeout for "logs element hiding filter dynamically" test

In https://gitlab.com/eyeo/adblockplus/abc/webext-sdk/-/tree/480-flaky_eh_dynamically (find the details in the https://gitlab.com/eyeo/adblockplus/abc/webext-sdk/-/issues/480 comments) i've received a better understanding of what's happening. The log event is actually emitted and elemhidden is actually scheduled and kinda finished (browser.*.insertCSS(..) promise is resolved). The actual problem is that the element is not element hidden within 10 seconds.

That happens with docker with limited resources only (i'm able to reproduce it time to time). Increasing the timeout actually helps (i was unable to reproduce it with larger timeout).

Another problem is that we don't know the way to calculate the reasonable and reliable value for the timeout as it depends on device performance and probably some other env conditions. 10 seconds sounded like a good idea previously and stopped working at some point. It can still happen with 25 seconds timeout next time. But that's another story.

Closes #480 (closed)