Fixes ScreenTimeoutSettingsTest

The recently added Battery Saver Preference need to be initialized in
order to avoid NPE in testing.

Bug: 188499083
Test: make RunSettingsRoboTests ROBOTEST_FILTER=com.android.settings.display

Change-Id: Ib6553bcf9ed86eb46c2e0950064e34439664a1ee

tests/robotests/src/com/android/settings/display/ScreenTimeoutSettingsTest.java

@@ -74,6 +74,9 @@ public class ScreenTimeoutSettingsTest {
     @Mock
     AdaptiveSleepCameraStatePreferenceController mAdaptiveSleepCameraStatePreferenceController;
 
+    @Mock
+    AdaptiveSleepBatterySaverPreferenceController mAdaptiveSleepBatterySaverPreferenceController;
+
     @Mock
     Preference mDisableOptionsPreference;
 
@@ -103,6 +106,8 @@ public class ScreenTimeoutSettingsTest {
         mSettings.mAdaptiveSleepPermissionController = mPermissionPreferenceController;
         mSettings.mAdaptiveSleepCameraStatePreferenceController =
                 mAdaptiveSleepCameraStatePreferenceController;
+        mSettings.mAdaptiveSleepBatterySaverPreferenceController =
+                mAdaptiveSleepBatterySaverPreferenceController;
     }
 
     @Test