Limit the number of license check and filter update requests

[vbagirov]

Currently they are too irritating with ~5 notifications a day.

Original request:
https://forum.adguard.com/index.php?threads/adguard-%D0%B4%D0%BB%D1%8F-android-%D0%91%D0%B5%D1%82%D0%B0-%D0%B2%D0%B5%D1%80%D1%81%D0%B8%D1%8F-2-6-23.10581/#post-83803

UPD: we don't have any "license expiring" notifications (why so btw?). So in this issue we'll do another useful thing: limit the number of license check requests.

Usually we do such request once in 12 or 24 hours. The problem is that currently when app is killed and restarted, timer is started over and first license check is scheduled on +5 min.

[Revertron]

But this is not our notification :-)

We do not have such icon and text.

[ameshkov]

Huh, do we have any notification?:)

[ameshkov]

Nevertheless, we should limit the number of any requests to our server.

Currently we just do it periodically once in 12 or 24 hours (don't remember then number). The problem is that if our app is killed by Android, timer is started over and first request is scheduled on +5 mins.

[Revertron]

Nope. I think we should make some :)

[ameshkov]

Haha, nice:)

[ameshkov]

Let's schedule it on v2.7 release.

[ameshkov]

@Revertron not this issue, make a separate one.

This one is renamed to "Limit the number of license check and filter update requests"

[Revertron]

Ah, okay.

[TPS]

My 2¢: If y'all don't mind (especially since #611 will probably increase server load some, anyway), but even 12 hours is probably too long an interval for a manual check. I can sometimes request a filter update 1 hour apart from my last 1, & get an update to several lists. (The English & German lists seem to have frequent updates!) Limiting the automatic checks _only_ would be my preference.

[ameshkov]

@TPS I mean the periodic automatic update check, manual checks have no limitations.

[Revertron]

Done!