Fix docs build by adding include <endian.h>

Added endian.h into include list to avoid build error in "docs".
The function "htobe64" in endian.h is used.

Change-Id: Ic76dab25d34c56b58b97849dfa7b103963392568
diff --git a/core/jni/android_hardware_SensorManager.cpp b/core/jni/android_hardware_SensorManager.cpp
index 9793cdb..f4237d2 100644
--- a/core/jni/android_hardware_SensorManager.cpp
+++ b/core/jni/android_hardware_SensorManager.cpp
@@ -13,28 +13,25 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
-
 #define LOG_TAG "SensorManager"
 
-#include <map>
+#include "JNIHelp.h"
+#include "android_os_MessageQueue.h"
+#include "core_jni_helpers.h"
+#include "jni.h"
 
 #include <ScopedUtfChars.h>
 #include <ScopedLocalRef.h>
-
+#include <android_runtime/AndroidRuntime.h>
+#include <gui/Sensor.h>
+#include <gui/SensorEventQueue.h>
+#include <gui/SensorManager.h>
 #include <utils/Log.h>
 #include <utils/Looper.h>
 #include <utils/Vector.h>
 
-#include <gui/Sensor.h>
-#include <gui/SensorManager.h>
-#include <gui/SensorEventQueue.h>
-
-#include "jni.h"
-#include "JNIHelp.h"
-#include "android_os_MessageQueue.h"
-#include <android_runtime/AndroidRuntime.h>
-
-#include "core_jni_helpers.h"
+#include <endian.h>   // htobe64
+#include <map>
 
 namespace {