Cache balance and load it on startup

[ovitrif]

Cache balance to disk and load it on startup, to avoid showing 0 balance for a brief moment on start.

startupWithCachedBalance.webm

[jvsena42]

Does the wallet has some logout flow? if yes, the balance should be cleared

[ovitrif]

Does the wallet has some logout flow? if yes, the balance should be cleared

Yes, good point!

It should already happen, here:

https://github.com/synonymdev/bitkit-android/blob/master/app/src/main/java/to/bitkit/viewmodels/WalletViewModel.kt#L334-L336