Get rid of _hats.py dependency in the JoyDemo.
Get rid of _hats.py dependency in the JoyDemo.

Change-Id: I0be781fd52186c7b7f40ba43c048a4efc7532f93

google/aiyprojects-raspbian,google/aiyprojects-raspbian,google/aiyprojects-raspbian,google/aiyprojects-raspbian,google/aiyprojects-raspbian