Improve the logic for determining agent aliveness

[intr3p1d]

The aliveness of an agent is now determined by the following logic:

If any of the conditions below are met, it should return true.

Determined from the AgentStatus object:

• The agent status is RUNNING
• The agent timestamp is within the Range.from ~ Range.to interval.

Determined from isActiveAgent:

• There is a status in the Jvm Gc Dao (isActiveAgentByGcStat).
• There is an Agent Ping (isActiveAgentByPing).

Previously, two conditions were connected with and. This resulted in unnecessary overhead.
Fix this first, and then improve isActiveAgent.