TW-346: Fix unlock after minimize

[alex-tsx]

• [tech] Fix postinstall script on Linux
• TW-346: Fix unlock after minimize. With bootsplash screen hiding earlier
• TW-346: Fix unlock after minimize. With disabling 'warm-up' in 'react-native-keychain'

[alex-tsx]

It seems that the issue lies entirely with user minimizing the app, when runtime entered Keychain.getGenericPassword but hasn't returned yet.

So the strategy to solve it was reducing the execution time of this method by installing react-native-keychain manually without warm-up mechanism:

• getGenericPassword is too slow on android 10 oblador/react-native-keychain#337
• Android UI freezing on launch oblador/react-native-keychain#314

See report of our particular behavior:

• getGenericPassword on Android sometimes fails and crashes app oblador/react-native-keychain#525 (comment)

Useful links:

• https://morioh.com/p/ee35f5c7a815
• https://github.com/oblador/react-native-keychain#configuring-the-android-specific-behavior

Some alternatives worth looking into:

• https://www.npmjs.com/package/expo-secure-store
• https://www.npmjs.com/package/react-native-sensitive-info