Sezame Wallet

We currently store mnemonic one device and encrypted it with user password with Async Storage feature. We have to move and use Encrypted Storage instead.

This module use Android EncryptedSharedPreferences and IOS Keychain which is a much more secure way to store secret. We will still use User password to add a second layer of security, bringing two encryption levels to store the very sensitive Mnemonic on the device.