Android: Add common function for adding/releasing native reference

webrtc/sdk/android/src/jni/jni_helpers.cc

Index: webrtc/sdk/android/src/jni/jni_helpers.cc
diff --git a/webrtc/sdk/android/src/jni/jni_helpers.cc b/webrtc/sdk/android/src/jni/jni_helpers.cc
index 9101b276f7a35211546d3fd4c81960699117ec4a..6e2360811d9cc45bae1c17f9a6d18b0cf17bc7dd 100644
--- a/webrtc/sdk/android/src/jni/jni_helpers.cc
+++ b/webrtc/sdk/android/src/jni/jni_helpers.cc
@@ -9,14 +9,14 @@
  */
 #include "webrtc/sdk/android/src/jni/jni_helpers.h"
 
-#include "webrtc/sdk/android/src/jni/classreferenceholder.h"
-
 #include <asm/unistd.h>
 #include <sys/prctl.h>
 #include <sys/syscall.h>
 #include <unistd.h>
 #include <vector>
 
+#include "webrtc/sdk/android/src/jni/classreferenceholder.h"
+
 namespace webrtc_jni {
 
 static JavaVM* g_jvm = nullptr;