Maintain state when app runs in background

**Is your feature request related to a problem? Please describe.**
When app is in background, i.e when user uses another app and then comes back, then beacon state is lost and map screen goes blank.

**Describe the solution you'd like**
When app is in background, navigation and updates should still be fetched. Infact, minimising the app when it's in background would be great to have (like we have in food delivery or ride hailing apps).

**Are you working on this? (Yes/No)**
No, this issue is open to be assigned