问题：
adb install -r Camera.apk
2864 KB/s (7603465 bytes in 2.592s)
Failure [INSTALL_FAILED_UPDATE_INCOMPATIBLE: Package com.mediatek.camera signatures do not match the previously installed version; ignoring!]
解决方法：
adb remount
adb shell
cd system/vendor/app/Camera/Camera.apk
rm system/vendor/app/Camera/Camera.apk
adb push Camera.apk system/vendor/app/Camera/Camera.apk
adb shell stop
adb shell start