NoSuchMethodError in ably-android for API lower than 24

[KacperKluka]

After upgrading the Java-WebSocket library to version 1.5.3 we've noticed SDK crashes on Android 21. After investigation, it turned out that the library's version 1.5.x is no longer compatible with Android below 24 due to this known issue. Luckily, there's also a workaround that we should implement to fix this problem.

┆Issue is synchronized with this Jira Bug by Unito