android usb 預設mtp,Android7.1預設打開mtp（mtk）

直接貼修改記錄代碼：

diff --git a/frameworks/base/services/usb/java/com/android/server/usb/UsbDeviceManager.java b/frameworks/b

index 23c60bb..8bb7604 100644

--- a/frameworks/base/services/usb/java/com/android/server/usb/UsbDeviceManager.java

+++ b/frameworks/base/services/usb/java/com/android/server/usb/UsbDeviceManager.java

@@ -455,7 +455,7 @@ functions = addFunction(functions, UsbManager.USB_FUNCTION_ACM);

@@ -1374,7 +1374,7 @@ functions = addFunction(functions, UsbManager.USB_FUNCTION_ACM);

@@ -1383,7 +1383,7 @@ functions = addFunction(functions, UsbManager.USB_FUNCTION_ACM);

diff --git a/packages/apps/Settings/src/com/android/settings/deviceinfo/UsbModeChooserActivity.java b/pack

index 7da4a3b..01f3d2f 100644

--- a/packages/apps/Settings/src/com/android/settings/deviceinfo/UsbModeChooserActivity.java

+++ b/packages/apps/Settings/src/com/android/settings/deviceinfo/UsbModeChooserActivity.java

@@ -54,7 +54,7 @@ public class UsbModeChooserActivity extends Activity {