Enable wakeup sensors.

SensorService should hold a wakelock till the app reads events from a wakeup sensor. Currently drivers hold a wakelock with a
timeout while delivering events from a wake up sensor like Significant Motion. This hack can be removed now.

Bug: 9774884
Change-Id: If3b5acb99c9cf0cd29012fcfa9d6b04c74133d01
diff --git a/include/android/sensor.h b/include/android/sensor.h
index b4e7ebe..86de930 100644
--- a/include/android/sensor.h
+++ b/include/android/sensor.h
@@ -157,7 +157,9 @@
             uint64_t        step_counter;
         } u64;
     };
-    int32_t reserved1[4];
+
+    uint32_t flags;
+    int32_t reserved1[3];
 } ASensorEvent;
 
 struct ASensorManager;