Update an icon for MtpDocumentsProvider.

BUG=27135431

Change-Id: Ic8619a533bdf2426fdf0d3691a883606fa027fb1

packages/MtpDocumentsProvider/AndroidManifest.xml

@@ -15,10 +15,12 @@
                 <action android:name="android.content.action.DOCUMENTS_PROVIDER" />
             </intent-filter>
         </provider>
-        
+
         <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">

packages/MtpDocumentsProvider/res/values/strings.xml

@@ -15,8 +15,10 @@
 -->
 
 <resources xmlns:xliff="urn:oasis:names:tc:xliff:document:1.2">
-    <!-- Title of the external storage application [CHAR LIMIT=32] -->
+    <!-- App title of MtpDocumentsProvider [CHAR LIMIT=32] -->
     <string name="app_label">MTP Host</string>
+    <!-- App title of DocumentsUI [CHAR LIMIT=32] -->
+    <string name="downloads_app_label">Downloads</string>
     <!-- Name of MTP root shown in UI. Please align the two strings (device
          model and storage name) in proper order in the language.
          [CHAR LIMIT=32] -->