Use resolution to round sensor event values

Add method to utilize a sensor's specified resolution value to ensure
data isn't provided that is more fine-grained than expected. This
helps mitigate sensor calibration fingerprinting attacks.

Bug: 147725937
Test: Verify accel sensor data isn't more fine grained than its
specified resolution

Change-Id: I81905cde22cc8429021ffb8318a222512ce01900
diff --git a/services/sensorservice/SensorDevice.h b/services/sensorservice/SensorDevice.h
index 24d03c6..04e6031 100644
--- a/services/sensorservice/SensorDevice.h
+++ b/services/sensorservice/SensorDevice.h
@@ -233,11 +233,13 @@
 
     void convertToSensorEvent(const Event &src, sensors_event_t *dst);
 
-    void convertToSensorEvents(
+    void convertToSensorEventsAndQuantize(
             const hardware::hidl_vec<Event> &src,
             const hardware::hidl_vec<SensorInfo> &dynamicSensorsAdded,
             sensors_event_t *dst);
 
+    float getResolutionForSensor(int sensorHandle);
+
     bool mIsDirectReportSupported;
 
     typedef hardware::MessageQueue<uint32_t, hardware::kSynchronizedReadWrite> WakeLockQueue;