Fix a missing item "String Type" in sensor info of Device Orientation.

Bug: 187917044
Test: Verify pass by checking if the item "String Type" exists by
following command:
adb shell sensor_test info 27

Change-Id: I52045186d4271892bd102bc4009aa2ae782d947d
diff --git a/libs/sensor/Sensor.cpp b/libs/sensor/Sensor.cpp
index 240738d..0a49008 100644
--- a/libs/sensor/Sensor.cpp
+++ b/libs/sensor/Sensor.cpp
@@ -231,6 +231,10 @@
             mFlags |= SENSOR_FLAG_WAKE_UP;
         }
         break;
+    case SENSOR_TYPE_DEVICE_ORIENTATION:
+        mStringType = SENSOR_STRING_TYPE_DEVICE_ORIENTATION;
+        mFlags |= SENSOR_FLAG_ON_CHANGE_MODE;
+        break;
     case SENSOR_TYPE_DYNAMIC_SENSOR_META:
         mStringType = SENSOR_STRING_TYPE_DYNAMIC_SENSOR_META;
         mFlags |= SENSOR_FLAG_SPECIAL_REPORTING_MODE; // special trigger