Android mtk 系统应用改为可卸载，恢复出厂可恢复

system/app或者priv-app目录下的系统应用需要可卸载

vendor/mediatek/proprietary/frameworks/base/data/etc/pms_sysapp_removable_system_list.txt
在文件中添加需要可卸载应用的包名

 com.android.quicksearchbox
 com.android.calendar
 com.android.dreams.basic
 com.android.musicfx
 com.android.calculator2
 com.android.email
 com.android.exchange
+com.android.fmradio

将systemapp改为可卸载后打开报错，如：

01-02 03:58:32.208: E/AndroidRuntime(12271): FATAL EXCEPTION: main
01-02 03:58:32.208: E/AndroidRuntime(12271): Process: com.android.fmradio, PID: 12271
01-02 03:58:32.208: E/AndroidRuntime(12271): java.lang.UnsatisfiedLinkError: dlopen failed: library "/system/priv-app/FMRadio/lib/arm/libfmjni.so" needed or dlopened by "/system/lib/libnativeloader.so" is not accessible for the namespace "classloader-namespace"
01-02 03:58:32.208: E/AndroidRuntime(12271): 	at java.lang.Runtime.loadLibrary0(Runtime.java:1016)
01-02 03:58:32.208: E/AndroidRuntime(12271): 	at java.lang.System.loadLibrary(System.java:1657)
01-02 03:58:32.208: E/AndroidRuntime(12271): 	at com.android.fmradio.FmNative.<clinit>(FmNative.java:24)
01-02 03:58:32.208: E/AndroidRuntime(12271): 	at com.android.fmradio.FmNative.openDev(Native Method)
01-02 03:58:32.208: E/AndroidRuntime(12271): 	at com.android.fmradio.FmService.openDevice(FmService.java:667)
01-02 03:58:32.208: E/AndroidRuntime(12271): 	at com.android.fmradio.FmService.onCreate(FmService.java:1485)
01-02 03:58:32.208: E/AndroidRuntime(12271): 	at android.app.ActivityThread.handleCreateService(ActivityThread.java:3380)
01-02 03:58:32.208: E/AndroidRuntime(12271): 	at android.app.ActivityThread.-wrap4(Unknown Source:0)
01-02 03:58:32.208: E/AndroidRuntime(12271): 	at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1711)
01-02 03:58:32.208: E/AndroidRuntime(12271): 	at android.os.Handler.dispatchMessage(Handler.java:106)
01-02 03:58:32.208: E/AndroidRuntime(12271): 	at android.os.Looper.loop(Looper.java:164)
01-02 03:58:32.208: E/AndroidRuntime(12271): 	at android.app.ActivityThread.main(ActivityThread.java:6548)
01-02 03:58:32.208: E/AndroidRuntime(12271): 	at java.lang.reflect.Method.invoke(Native Method)
01-02 03:58:32.208: E/AndroidRuntime(12271): 	at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:438)
01-02 03:58:32.208: E/AndroidRuntime(12271): 	at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:857)

将需要引用的so库添加到system/core/rootdir/etc/public.libraries.android.txt 文件中

 libandroid.so
 libaaudio.so
 libc.so
 libcamera2ndk.so
 libdl.so
 libEGL.so
 libGLESv1_CM.so
 libGLESv2.so
 libGLESv3.so
 libicui18n.so
 libicuuc.so
 libjnigraphics.so
 liblog.so
 libmediandk.so
 libm.so
 libnativewindow.so
 libneuralnetworks.so
 libOpenMAXAL.so
 libOpenSLES.so
 libRS.so
 libstdc++.so
 libsync.so
 libvulkan.so
 libwebviewchromium_plat_support.so
 libz.so
+libfmjni.so