fix: Discard persisted state on Android Activity restart

PlayStore console reported some crashes related to react-native-screens
that are related to Activity's `onCreate` method

This bug is well documented in the react-native-screens repository and
the recommended action is to discard the Activity's persisted state
when restarted

This is because the JS state (redux stores, in-component state etc) is
not persisted the same way as the Android activity state, so there can
be some inconsistencies between them when the app is restarted

Discarding the state implies that if Android kills the Activity when
app is on background, then on when going back to the app it will behave
like if it was a fresh start

Another impact is for foldable phones in which the app will restart
when splitted into multi-window. But as the app does not support this
mode, then this would not be an issue (at least for now)

Related documentation:
https://github.com/software-mansion/react-native-screens#android

Related issue:
software-mansion/react-native-screens#17

android/app/src/main/java/io/cozy/flagship/mobile/MainActivity.java

@@ -21,7 +21,7 @@ protected String getMainComponentName() {
   protected void onCreate(Bundle savedInstanceState) {
     boolean isDarkMode = true;
     ImmersiveBars.changeBarColors(this, isDarkMode);
-    super.onCreate(savedInstanceState);
+    super.onCreate(null);
     RNBootSplash.init(R.drawable.bootsplash, MainActivity.this);
   }
 }