This test will provide RawEvent's to TouchpadInputMapper and will look
at the returned events.

The main purpose of this CL is to document the existing behaviour of
CursorInputMapper and TouchpadInputMapper. The tests highlights that
today, dispatcher must handle the case where the touch starts without
HOVER_EXIT. That means that the dispatcher logs of "conflicting pointer
actions" can be mostly ignored.

The goal was to make the tests for the two mappers as similar to each
other as possible.

A slightly different testing infra is introduced here compared to the
one used in InputReader_test.

Changes:
* Use mocks for interfaces instead of constructed objects
This helps figure out which parts are important to mock for a specific
test vs which ones are not. When a function is called with a parameters
that the mocks aren't expecting, a warning is printed during test run.
This helps identify the complete state needed in order for the test to
execute.

* No longer require InstrumentedInputReader

* No longer require a listener. We only check the events that are coming
  from the 'process' call, which is what the interface for the mapper
  does.

Limitations:
* Still require an InputDevice object to be constructed in order to test
  InputMappers. Ideally, a mapper would only depend on the EventHub
  state (to read the current value of keys / axes after a reset).

Bug: 263319225
Test: m inputflinger_tests && $ANDROID_HOST_OUT/nativetest64/inputflinger_tests/inputflinger_tests --gtest_filter="*HoverAndLeftButtonPress*"
Change-Id: I7de0dee7abcf6bcb9d3283e29d9a85de2f331a44