simpleperf: add run_simpleperf_on_device.py.

It is added mainly to show in README.md how to detect whether
trace-offcpu is supported on device, by
 `python run_simpleperf_on_device.py list --show-features`.

Bug: http://b/32834638
Test: run test.py.
Change-Id: I33a6fb81b650293faec233eb6a735bac7cb5e215
4 files changed