fix: update lastActiveTimestamp value when reset call is made

Description

Refactor variable and method name: updateLastEventTimeStamp to updateLastActiveTimestamp.
Fix: Update the last active timestamp value when the RESET call is made. This will prevent the SDK from generating a new sessionId, when the app is relaunched following a force close after a RESET call has been made. (Note: This fix might be temporary and we can decide to change it based on further discussion.)

Fixes # (issue)

[x] 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