Re-word "Disallow USB File Transfer" manual test.

The existing manual test instructions assume that the device is capable of
USB file transfer using MTP or PTP, and aim to ensure that disallowing
file transfer indeed blocks that option.

The new instructions allow for devices that don't support MTP or PTP at
all, and also clarify that 'adb pull' doesn't count as "USB file
transfer" in this context.

Bug: 32335136
Change-Id: Iab4eaa13b116871876ad5a590136f54e58029fc8
diff --git a/apps/CtsVerifier/res/values/strings.xml b/apps/CtsVerifier/res/values/strings.xml
index 6f379f8..dfc5254 100755
--- a/apps/CtsVerifier/res/values/strings.xml
+++ b/apps/CtsVerifier/res/values/strings.xml
@@ -2171,9 +2171,12 @@
     <string name="device_owner_disallow_usb_file_transfer_test">Disallow USB file transfer</string>
     <string name="device_owner_disallow_usb_file_transfer_test_info">
             Please press below button to set the \"disallow USB file transfer\" restriction.\n
-            Next, connect your device to your desktop computer through USB, open the USB notification from the status bar
-            and check that the \"Transfer files (MTP)\" and \"Transfer photos (PTP)\" cannot be selected and triggers a support message when trying to select them.\n
-            Also, check that if you can download files from your phone to the desktop computer. The test is successful if the files from your phone are not and cannot be downloaded through USB.\n
+            If a USB notification appears, open the notification and check that the
+            \"Transfer files (MTP)\" and \"Transfer photos (PTP)\" cannot be selected and trigger a
+            support message when trying to select them.\n
+            Check if you can mount the device as a USB drive on your desktop computer. The test is
+            successful if you cannot mount the device, and files from your phone cannot be
+            downloaded through USB.\n
             Please mark the test accordingly.
     </string>
     <string name="device_owner_set_user_icon">Setting the user icon</string>