simpleperf: app_profiler.py: add --launch option

Starting an app using `-a` needs to know its launch activity
name. It may not be convenient. So add `--launch` to start
an app only with its package name.

Bug: none
Test: run test.py -p *test_recording_endless_tunnel
Change-Id: I4475385775e8fb9d956de12de0f8dee31dd9019a
2 files changed