(Issue title)

[dual-sim mode] between introducing both PINs there's a gap

Summary

First thing after booting an /e/-phone: the user need to type the PIN code to unlock his/her SIM card. In case, 2 SIM cards are used, both SIM cards need to be unlocked by PIN codes. There's a tiny issue when introducing the second SIM card

Steps to reproduce

Reboot phone Type PIN code 1 on the first input screen

• Now input screen 2 is appearing right after and the user may type PIN code 2,
• Only a second later the phone's home screen is shown briefly and
• then input screen 2 pops-up again.

If the second PIN code was typed-in in this second before the home screen appeared briefly, the typed-in PIN vanishes.

What is the expected correct behavior?

• Input screen 1
• Only when PIN 1 was entirely processed, input screen 2 should appear (in case it is necessary for technical reasons to show briefly the homescreen, input screen 2 should ONLY appear afterwards.

There should be no possibility where there user may type something that cannot be noted by the system at that very moment.