constify JNINativeMethod function pointer tables

Change-Id: I4036c924958221cbc644724f8eb01c5de3cd7954
diff --git a/core/jni/android_opengl_GLES31Ext.cpp b/core/jni/android_opengl_GLES31Ext.cpp
index 2856308..180c693 100644
--- a/core/jni/android_opengl_GLES31Ext.cpp
+++ b/core/jni/android_opengl_GLES31Ext.cpp
@@ -1443,7 +1443,7 @@
 
 static const char *classPathName = "android/opengl/GLES31Ext";
 
-static JNINativeMethod methods[] = {
+static const JNINativeMethod methods[] = {
 {"_nativeClassInit", "()V", (void*)nativeClassInit },
 {"glBlendBarrierKHR", "()V", (void *) android_glBlendBarrierKHR__ },
 {"glDebugMessageControlKHR", "(IIII[IIZ)V", (void *) android_glDebugMessageControlKHR__IIII_3IIZ },