[Enhancement] Purge every agent after X amount of runs

[peterzhuamazon]

We currently set purging for gradle check agent (every 1 run), and windows agents (every 10 runs).

We should do this for the other agents, as some of them would stay for over a month and have OOM issues after all the runs without proper cleanups.

Thanks.

[peterzhuamazon]

A follow up:

• [Enhancement] Add possible monitoring and metrics to decide the lifecycle of the Agent Nodes #498