SeedGenerator()
This is intentionally insecure. Wallet makers have told us storing keys is their specialty so we don't put a lot of energy here. A true implementation would create a key using user interaction, perhaps with a password they know that is never stored, along with requiring user authentication for key use (i.e. fingerprint/PIN/pattern/etc). From there, one of these approaches might be helpful to store the key securely:
https://developer.android.com/training/articles/keystore.html https://github.com/scottyab/AESCrypt-Android/blob/master/aescrypt/src/main/java/com/scottyab/aescrypt/AESCrypt.java https://github.com/iamMehedi/Secured-Preference-Store