constify JNINativeMethod function pointer tables

Change-Id: I4036c924958221cbc644724f8eb01c5de3cd7954
diff --git a/media/jni/android_mtp_MtpServer.cpp b/media/jni/android_mtp_MtpServer.cpp
index 2ce2a90..d13187c 100644
--- a/media/jni/android_mtp_MtpServer.cpp
+++ b/media/jni/android_mtp_MtpServer.cpp
@@ -179,7 +179,7 @@
 
 // ----------------------------------------------------------------------------
 
-static JNINativeMethod gMethods[] = {
+static const JNINativeMethod gMethods[] = {
     {"native_setup",                "(Landroid/mtp/MtpDatabase;Z)V",
                                             (void *)android_mtp_MtpServer_setup},
     {"native_run",                  "()V",  (void *)android_mtp_MtpServer_run},