Add initial batch of inputFlinger fuzzers

This batch of fuzzers is focused on the input Mappers. These fuzzers are
not host_supported, and must be run on-device. Followup CLs containing
additional inputflinger fuzzers will rely on the FuzzContainer.h and
MapperHelpers.h header files.

Fuzzers included:
 - CursorInputFuzzer
 - KeyboardInputFuzzer
 - MultiTouchInputFuzzer
 - SwitchInputFuzzer

Test: Tested on a pixel 3a with HWASAN. Accurate % coverage information is
      not available due to the large number of shared libraries included
      in runs built with hwasan interfering with PC Count information
      (increasing the total PC count to ~682,000).

Summary of updates:

Coverage improvements: 75% to 82%

Design changes:
[1] Refactored
 - CursorInputFuzzer
 - KeyboardInputFuzzer
 - MultiTouchInputFuzzer
 - SwitchInputFuzzer
in order to generate event as a combination of valid and invalid input.

[2] Used FuzzedDataProvider to generate values for events.

Signed-off-by: Michael Ensing <michael.ensing@leviathansecurity.com>
Change-Id: Id39205c691f54c516f8a452293cb098382019335