USB: Make MTP/PTP toggle in the USB preferences set the default mode

Change-Id: I438f7f24f06298ad41a99199c26c45bd7884afdd
Signed-off-by: Mike Lockwood <lockwood@android.com>
diff --git a/packages/SystemUI/src/com/android/systemui/usb/UsbPreferenceActivity.java b/packages/SystemUI/src/com/android/systemui/usb/UsbPreferenceActivity.java
index 3ed44e8..187a486 100644
--- a/packages/SystemUI/src/com/android/systemui/usb/UsbPreferenceActivity.java
+++ b/packages/SystemUI/src/com/android/systemui/usb/UsbPreferenceActivity.java
@@ -78,8 +78,10 @@
         if (v.equals(mMtpPtpButton)) {

             if (mPtpActive) {

                 mUsbManager.setPrimaryFunction(UsbManager.USB_FUNCTION_MTP);

+                mUsbManager.setDefaultFunction(UsbManager.USB_FUNCTION_MTP);

             } else {

                 mUsbManager.setPrimaryFunction(UsbManager.USB_FUNCTION_PTP);

+                mUsbManager.setDefaultFunction(UsbManager.USB_FUNCTION_PTP);

             }

         } else if (v.equals(mInstallerCdButton)) {

             mUsbManager.setPrimaryFunction(UsbManager.USB_FUNCTION_MASS_STORAGE);