Telegram channels support for Android databases (#2134)

[wladimirleite]

Closes #2134.

[lfcnassif]

Thanks @wladimirleite!

[lfcnassif]

I'm waiting for a regression test on 150 Telegram DBs to finish, so we can merge this.

[lfcnassif]

Master extracted ~2.4K more messages (from ~2.3M), but from iOS DBs, not from Android DBs. I had a "disk full" issue while processing and resumed it, so possibly that difference is related to resuming. I'll run again the failed processing with master to make sure everything is fine, looking at the code seems iOS processing wasn't changed.

[wladimirleite]

There were some changes in the common part of the code, also used when parsing Telegram iOS databases, but in theory it shouldn't affect the number of messages. Obviously it possible that some regression was introduced. Let me know about the results when the tests finish.

[lfcnassif]

The test finished, everything looks fine, thank you @wladimirleite!