Add companion test instruction to turn on bluetooth

Bug: 63068644
Test: proofread (strings-only change)
Change-Id: Id071ec8582230cf4c0c22a413d7fdcf27f14f57c
diff --git a/apps/CtsVerifier/res/values/strings.xml b/apps/CtsVerifier/res/values/strings.xml
index 45e1ff3..709632d 100755
--- a/apps/CtsVerifier/res/values/strings.xml
+++ b/apps/CtsVerifier/res/values/strings.xml
@@ -479,6 +479,7 @@
         including showing the dialog to the user to verify a device, as well as updating an internal
         record once the user made the choice and then removing it.\n\n
         Before proceeding, make sure you have a bluetooth device nearby and discoverable.
+        Also, make sure that bluetooth is turned on on this device.
         Once you press the button, wait for a dialog to pop up and select your device from the list.
     </string>