Add some synchronous input trace points.

This CL adds the following trace points.
1) a synchronous trace point for "deliverInputEvent", which can include
some additional metadata w/o spamming systrace and perfetto UI. Note
this trace ends when either an asynchornous input stage defers the input
event, which is earlier than the asynchronous "deliverInputEvent".
2) a trace point for consistency verifier and unhandled key manager
each.
3) onProcess() of each input stage. It doesn't include the actual
process time of asynchronous input stages, but it's not hard to get a
sense of it when looking at all trace points together.

Bug: 142003033
Test: systrace includes traces for input stages for both touch events
(touchscreen) and key events (keyboard).

Change-Id: I1b416423d37486df9ff23856c676bc7dab7765be