sensorservice can now be ran standalone

Change-Id: I6e757f31f1e020046038e5ab84e71b8689a0aed3
diff --git a/cmds/system_server/library/system_init.cpp b/cmds/system_server/library/system_init.cpp
index b615764..a19711e 100644
--- a/cmds/system_server/library/system_init.cpp
+++ b/cmds/system_server/library/system_init.cpp
@@ -70,8 +70,11 @@
         SurfaceFlinger::instantiate();
     }
 
-    // Start the sensor service
-    SensorService::instantiate();
+    property_get("system_init.startsensorservice", propBuf, "1");
+    if (strcmp(propBuf, "1") == 0) {
+        // Start the sensor service
+        SensorService::instantiate();
+    }
 
     // On the simulator, audioflinger et al don't get started the
     // same way as on the device, and we need to start them here