Fix ContextualAdaptiveSleepSliceTest

ADAPTIVE_SLEEP has been moved from Settings.System to Settings.Secure
but the main logic hasn't synced with the change which leads to the
failure.

Fixes: 139319542
Test: robotests
Change-Id: I56f58cc3da5a4034e2bf2ed5a63ae3bc2fec2a21
1 file changed