CCDWA-113 Show shielding notice once per app start

[Radiokot]

Purpose

Show shielding notice once per app start

Changes

• Show shielding notice once per app start

Checklist

• My code follows the style of this project.
• The code compiles without warnings.
• I have performed a self-review of the changes.
• I have documented my code, in particular the intent of the
  hard-to-understand areas.

[github-actions]

File	Coverage [3.55%]	❌
AuthPreferences.kt	4.91%	❌
Session.kt	0%	❌

Total Project Coverage	1.01%	❌

[github-actions]

File	Coverage [3.55%]	❌
AuthPreferences.kt	4.91%	❌
Session.kt	0%	❌

Total Project Coverage	1.01%	❌