open /dev/fm fail

[DESCRIPTION]
L版本使用fm app时遇到open /dev/fm fail问题，从log来看/dev/fm这个设备节点打开失败，失
败原因是节点的访问权限问题，如下红色字体内容：
Line 14637: 01-02 09:06:19.878 3563 3592 I FMLIB_COM: COM_open_dev start
Line 14638: 01-02 09:06:19.880 3563 3592 E FMLIB_COM: Open /dev/fm failed, Permission denied
Line 14638: 01-02 09:06:19.880 3563 3592 E FMLIB_COM: Open /dev/fm failed, Permission denied
Line 14639: 01-02 09:06:19.880 3563 3592 I FMLIB_COM: int COM_open_dev(const char*, int*), [fd=-1]
[ret=-1007]
Line 14640: 01-02 09:06:19.880 3563 3592 E FMLIB_CORE: int FMR_open_dev(int) failed, [fd=-1]
Line 14640: 01-02 09:06:19.880 3563 3592 E FMLIB_CORE: int FMR_open_dev(int) failed, [fd=-1]
Line 14641: 01-02 09:06:19.880 3563 3592 D FMLIB_JNI: jboolean openDev(JNIEnv*, jobject), [ret=-1007]
Line 14642: 01-02 09:06:19.880 3563 3592 E FM/FMRadioService: Error: opendev failed
[SOLUTION]
1. 在alps\vendor\mediatek\proprietary\packages\apps\FmRadio\android.mk
修改LOCAL_CERTIFICATE := platform， 原先是media。
2. 在alps\vendor\mediatek\proprietary\packages\apps\FmRadio\ AndroiDMAnifest.xml中添加
<uses-permission android:name="android.permission.ACCESS_FM_RADIO" /
3. 在device/mediatek/common/sepolicy/system_app.te 里面添加下面这行
allow system_app fm_device:chr_file { read write ioctl open};

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