Move turnScreenOff to BeforeClass setUp

A Thread.sleep() is needed after turnScreenOff() to ensure APF has
started running. This means it makes sense to move turnScreenOff to
a @BeforeClass setup to avoid slowing down the tests.

Test: atest ApfIntegrationTest
Change-Id: Ie1d9335fb1ad2ac3c51a48269b28f66f212f993c
1 file changed