fix: rudder preference manager refactor

[1abhishekpandey]

Description

Fixed the following issues:

• UserId was being sent as an empty field. Now, it will not be sent if it is empty.
• Fixed lifecycle logic.
• Modified getInt in Shared Preferences to return -1 when the value is not found.
• Implemented custom getters for all fields in Storage to ensure the latest values are fetched.

Fixes # (issue)

Type of change

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• This change requires a documentation update

Checklist:

• Version upgraded (project, README, gradle, podspec etc)
• My code follows the style guidelines of this project
• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• I have added unit tests for the code
• I have made corresponding changes to the documentation

[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarCloud