Add ReceiverActivity to MtpDocumentsProvider.

                <action android:name="android.content.action.DOCUMENTS_PROVIDER" />

            </intent-filter>

        </provider>

        <activity android:name=".ReceiverActivity"

                  android:theme="@android:style/Theme.NoDisplay"

                  android:screenOrientation="locked"

                  android:excludeFromRecents="true"

                  android:enabled="false">

            <intent-filter>

                <action android:name="android.hardware.usb.action.USB_DEVICE_ATTACHED" />

            </intent-filter>

            <meta-data android:name="android.hardware.usb.action.USB_DEVICE_ATTACHED"

                       android:resource="@xml/device_filter" />

        </activity>

        <service android:name=".MtpDocumentsService"></service>

    </application>

</manifest>

<?xml version="1.0" encoding="utf-8"?>

<!-- Copyright (C) 2015 The Android Open Source Project

     Licensed under the Apache License, Version 2.0 (the "License");

     you may not use this file except in compliance with the License.

     You may obtain a copy of the License at

          http://www.apache.org/licenses/LICENSE-2.0

     Unless required by applicable law or agreed to in writing, software

     distributed under the License is distributed on an "AS IS" BASIS,

     WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

     See the License for the specific language governing permissions and

     limitations under the License.

-->

<resources>

    <!-- filter for MTP/PTP devices -->

    <usb-device class="255" subclass="255" protocol="0" />

    <usb-device class="6" subclass="1" protocol="1" />

</resources>

/*

 * Copyright (C) 2015 The Android Open Source Project

 *

 * Licensed under the Apache License, Version 2.0 (the "License");

 * you may not use this file except in compliance with the License.

 * You may obtain a copy of the License at

 *

 *      http://www.apache.org/licenses/LICENSE-2.0

 *

 * Unless required by applicable law or agreed to in writing, software

 * distributed under the License is distributed on an "AS IS" BASIS,

 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

 * See the License for the specific language governing permissions and

 * limitations under the License.

 */

package com.android.mtp;

import android.app.Activity;

import android.content.Intent;

import android.hardware.usb.UsbManager;

import android.os.Bundle;

/**

 * Invisible activity to receive intents.

 * To show the application chooser for the UsbManager.ACTION_USB_DEVICE_ATTACHED intent, the intent

 * should be received by activity. The activity has NoDisplay theme and immediately terminate after

 * routing intent to MtpDocumentsService.

 */

public class ReceiverActivity extends Activity {

    @Override

    protected void onCreate(Bundle savedInstanceState) {

        super.onCreate(savedInstanceState);

        if (UsbManager.ACTION_USB_DEVICE_ATTACHED.equals(getIntent().getAction())) {

            final Intent serviceIntent = new Intent(

                    MtpDocumentsService.ACTION_OPEN_DEVICE,

                    null,

                    this,

                    MtpDocumentsService.class);

            serviceIntent.putExtra(

                    UsbManager.EXTRA_DEVICE,

                    getIntent().getParcelableExtra(UsbManager.EXTRA_DEVICE));

            startService(serviceIntent);

        }

        finish();

    }

}