constify JNINativeMethod function pointer tables

Change-Id: I4036c924958221cbc644724f8eb01c5de3cd7954
diff --git a/core/jni/android_hardware_camera2_CameraMetadata.cpp b/core/jni/android_hardware_camera2_CameraMetadata.cpp
index 7c8769d..43795b8 100644
--- a/core/jni/android_hardware_camera2_CameraMetadata.cpp
+++ b/core/jni/android_hardware_camera2_CameraMetadata.cpp
@@ -505,7 +505,7 @@
 
 //-------------------------------------------------
 
-static JNINativeMethod gCameraMetadataMethods[] = {
+static const JNINativeMethod gCameraMetadataMethods[] = {
 // static methods
   { "nativeClassInit",
     "()V",