Add the ability to am to be able to track binder transact calls. This
will help us diagnose excessive IPC calls.
This CL adds the trace-ip command to am. The usage is,
To start binder transaction tracking,
am trace-ipc start
To stop tracking and dump the data to a file,
am trace-ipc stop --dump-file <FILE>
Bug: 21398706
Change-Id: Ic0c9b3be757dd0662a2750a0d8447e2a5ef1fa90