I have been searching and have found out, that android supports only SQLite databse and no other. Is this true?
Yes. The Android library provides native support to only SQLite. Of course, this doesn’t mean you absolutely can’t use other databases on Android; if you need to use other databases, you’ll have to either look for already-existing third-party libraries(1), or roll out your own API.
(1) Careful there: If you look for third-party libraries, make sure they’re built specifically for Android, since Android includes only a subset of the Java standard library. If they’re not specifically built for Android, there’s a possibility that the libraries won’t work due to missing classes.