libaurum: Applying strategy pattern for OCP

libaurum: Applying strategy pattern for OCP

Existing code was violating the SOLID principle OCP by being closed for additional events.

To solve this problem, the strategy pattern was applied so that even if new events were added,
the existing business logic remained unchanged and the structure was improved so that new classes could be added.

Change-Id: I386ef353d9a0427dc8e32a89fb1e386a30bafc76