Don't create if not primary user

PhoneGlobals is instantiated only for primary users so check for
attempts to bring up this settings screen for non-primary users.

Bug:18354968
Change-Id: I449287603de51c7a42fc3ca27b8b46681129f6bb
diff --git a/res/values/strings.xml b/res/values/strings.xml
index fabb30b..db68ecb 100644
--- a/res/values/strings.xml
+++ b/res/values/strings.xml
@@ -264,6 +264,8 @@
 
     <!-- Title of the progress dialog displayed while updating Call settings -->
     <string name="updating_title">Call settings</string>
+    <!-- Toast in Call settings when asked to launch settings for a secondary user -->
+    <string name="call_settings_primary_user_only">Call settings can only be changed by the primary user.</string>
     <!-- Title of the "Call settings" settings screen, with a text label identifying which SIM the settings are for. -->
     <string name="call_settings_with_label">Call settings (<xliff:g id="subscriptionlabel" example="Verizon">%s</xliff:g>)</string>
     <!-- Title of the alert dialog displayed if an error occurs while updating Call settings -->