Sensor: Implement ALS flush function

Add ambient light sensor HAL flush function need by android wear,
add flush event data to event data queue for polling.

Change-Id: Iaa6b8c818f07242dc09bf281445b2e1f4d0231f4
Tracked-On: https://jira01.devtools.intel.com/browse/MARVIN-627
Signed-off-by: Baixing Tan <[email protected]>
Reviewed-on: https://android.intel.com:443/363333
diff --git a/als/AlsSensor.h b/als/AlsSensor.h
index a393b0b..3bf726f 100644
--- a/als/AlsSensor.h
+++ b/als/AlsSensor.h
@@ -54,6 +54,7 @@
     virtual bool hasPendingEvents() const;
     virtual int setDelay(int32_t handle, int64_t ns);
     virtual int enable(int32_t handle, int enabled);
+    virtual int isActivated(int handle);
 #ifdef HAL_VERSION_GT_1_0
     virtual int batch(int handle, int flags, int64_t period_ns, int64_t timeout);
 #endif