Sensor: Make getId() more varied

Apps from different developers will now receive a different
ID for the same dynamic sensor.  Additionally, all apps
will now receive a different/new ID for the same dynamic
sensor after a factory reset.

Bug: 28775590, 29547335
Change-Id: I368655b0e4bdc16736a7fd163ea3f7dad2886b3b
diff --git a/services/sensorservice/SensorService.h b/services/sensorservice/SensorService.h
index 0d04478..c8de621 100644
--- a/services/sensorservice/SensorService.h
+++ b/services/sensorservice/SensorService.h
@@ -208,6 +208,17 @@
     status_t resetToNormalMode();
     status_t resetToNormalModeLocked();
 
+    // Transforms the UUIDs for all the sensors into proper IDs.
+    void makeUuidsIntoIdsForSensorList(Vector<Sensor> &sensorList) const;
+    // Gets the appropriate ID from the given UUID.
+    int32_t getIdFromUuid(const Sensor::uuid_t &uuid) const;
+    // Either read from storage or create a new one.
+    static bool initializeHmacKey();
+
+
+    static uint8_t sHmacGlobalKey[128];
+    static bool sHmacGlobalKeyIsValid;
+
     SensorList mSensors;
     status_t mInitCheck;