ANDROID-2122. Moved authorizeDeviceFromSession to JiveCore.

Also made all classes use @ParametersAreNonNullByDefault and ensured that all method return values were marked as @Nonnull or @Nullable.

Change-Id: I67b543c2de5df7468645bb08ec50ce49630f0fc7
ANDROID-2123. Moved deauthorizeDevice into JiveCore.

Change-Id: I9eaf5c81572faa2e857eab617c739b1e07f439cf