TAPL: Verifying some interactions with system

Investigation of TAPL failures, especially flakes is complex, partially
because it’s hard to tell whether it’s Launcher who is wrong or the
system.

We need to introduce a framework that looks at Launcher interaction with
the system and reports when interactions deviate from the expected
course, and who made the first wrong step.

This is first, proof-of-concept CL.

It analyzes long-press events. We had multiple cases when long-presses
didn’t happen or happened unexpectedly.

Launcher registers the events, TAPL retrieves and compares against the
sequence of expected regular expressions. This diagnostic is used when
something fails and at the end of public methods.

Change-Id: I07aa3a027267c03422c99c73ccd8808445c55fe8