LockAgent: Add agent parameters to start_lock_agent script

Add parsing of "--agent-options" parameter to configure optional agent
features.

Sample: adb shell setprop wrap.system_server "start_with_lockagent --agent-options native_crash,java_crash"

Test: m
Test: manual
Change-Id: Ie70d0155096838782cb76f8111a42eba0c20e75d