Fix a JNI local reference leak in MediaDrm

A reference leak was found in the subtitle usecase that also
applies to android_media_MediaDrm.cpp
(Code taken from the similar fix in android_media_MediaPlayer.cpp)

Change-Id: Icc4b25e4adc9a600ff4ac99a7a8478bb55a6e348
fb: add config.xml option to permanently force permanent menu key

devices like m7 are a kind of hybrid between navbar and hw key devices and
need a menu button in applications although it is categorized as a hw key
device. Give an option to permanently enable the menu key via overlay

Change-Id: I926b1b864e544c51fb225918022730ccab3698b6
fb: fix force permanent menu button

derp from my side, was not functional due of reversed
logic

Change-Id: I048fac2aa45ebcbf8716423975935258e24021d1