Add max stack depth to agent

As a stack depth limit to the ti-alloc-sample agent.  This will allow
the invocation to control how deep the stacks are, permitting better
flamegraphs.

Bug: none
Test: attach the agent; run the startop test; look at the log.
Change-Id: I3cee52c20c7e5034f5823a73ad8e2ce7efe42faa
2 files changed