Toggle screen state before and after ApfIntegrationTest

APF is supposed to run when the screen is off. This change turns the
screen off as part of setUp() and turns it back on in tearDown() (since
apparently CTS is run with the screen on as some tests rely on it).

turnScreenOn() / turnScreenOff() also acquire / release a partial
wakelock to prevent the CPU from suspending during the test.

Test: atest ApfIntegrationTest
Change-Id: I31f04f4d39284be387006fdd9d0a7c0e27feddb5
1 file changed