Update libsignal-android lib

[erxson]

I am not an expert, but recently 0.42 version of the library was released, but KryptEY is still on 0.21.1 and it seems that it is worth updating. SignalProtocolStore now extends the new KyberPreKeyStore interface, whose methods are missing in the SignalProtocolStoreImpl class.

Thank you for this cool app!

[amnesica]

Hi @erxson,

thanks for the info, at the moment I'm occupied with another project, but its on my todo list :)

Kind regards,
amnesica