Add ACCESS_MTP permission to Shell for CTS test coverage

Bug: 183377919
Test: atest CtsScopedStorageHostTest
Change-Id: Ic66617e66fd88302ee82bfeb217f9b7bf9b3776b
diff --git a/packages/Shell/AndroidManifest.xml b/packages/Shell/AndroidManifest.xml
index d5a5df0..d48b9b1 100644
--- a/packages/Shell/AndroidManifest.xml
+++ b/packages/Shell/AndroidManifest.xml
@@ -44,6 +44,8 @@
     <uses-permission android:name="android.permission.HIGH_SAMPLING_RATE_SENSORS" />
     <!-- ACCESS_BACKGROUND_LOCATION is needed for testing purposes only. -->
     <uses-permission android:name="android.permission.ACCESS_BACKGROUND_LOCATION" />
+    <!-- ACCESS_MTP is needed for testing purposes only. -->
+    <uses-permission android:name="android.permission.ACCESS_MTP" />
     <uses-permission android:name="android.permission.ACCESS_LOCATION_EXTRA_COMMANDS" />
     <uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />
     <uses-permission android:name="android.permission.ACCESS_WIFI_STATE" />