Add heading to sensors_event_t

Bug: 189983308
Test: compile (definitions only)
Change-Id: I01b75ecae37755bf43321d99e465a9dc42e2e318
diff --git a/include/hardware/sensors.h b/include/hardware/sensors.h
index 589aba0..a8bc4ec 100644
--- a/include/hardware/sensors.h
+++ b/include/hardware/sensors.h
@@ -359,6 +359,14 @@
 } limited_axes_imu_uncalibrated_event_t;
 
 /**
+ * Heading event data
+ */
+typedef struct {
+  float heading;
+  float accuracy;
+} heading_event_t;
+
+/**
  * Union of the various types of sensor data
  * that can be returned.
  */
@@ -452,6 +460,9 @@
              * SENSOR_TYPE_ACCELEROMETER_LIMITED_AXES_UNCALIBRATED for details.
              */
             limited_axes_imu_uncalibrated_event_t limited_axes_imu_uncalibrated;
+
+            /* heading data containing value in degrees and its accuracy */
+            heading_event_t heading;
         };
 
         union {