[WoC] Services - Create a SharedPreferences service

[Thesmader]

Minimum requirements for the service:

1. A function to return an instance of SharedPreferences.
2. A function(private to the service) to save different types of content to disk using SharedPreferences.

Reference

[Chinmay-KB]

To add to what @Thesmader has mentioned, make sure every fetch operation you make is checked with containsKey

[Chinmay-KB]

Sometimes we need to clear a bunch of keys, like

• Deleting theory and practical sections while resetting section
• Reset all data while logging out
  Have functions in this service that can achieve the said functionality in one click, currently all the keys that need to be deleted are called individually and deleted