Update an icon for MtpDocumentsProvider.

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

        <activity android:name=".ReceiverActivity"

                  android:label="@string/downloads_app_label"

                  android:icon="@mipmap/ic_launcher_download"

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

                  android:screenOrientation="locked"

                  android:excludeFromRecents="true">