Remove hardcoded URL string

* Details on URLs in the credential management
  app preference should be translatable.
* Remove hardcoded text and introduce strings.

Manual testing
* Download TestDPC and select 'Request to
  manage credentials'.
* Select allow.
* Go to Settings Credential management app
  preference and verify URL strings are displayed
  correctly.

Bug: 170627997
Test: manual testing
Change-Id: Iadff0c136064dabc3f77e30b46356126d657397f

res/values/strings.xml

@@ -6522,6 +6522,11 @@
     <string name="certificate_management_app_description">Certificates installed by this app identify you to the apps and URLs below</string>
     <!-- Label for button to remove the credential management app [CHAR LIMIT=30] -->
     <string name="remove_credential_management_app">Remove</string>
+    <!-- List item found in the credential management app's authentication policy [CHAR LIMIT=NONE] -->
+    <plurals name="number_of_urls">
+        <item quantity="one"><xliff:g id="number">%d</xliff:g> URL</item>
+        <item quantity="other"><xliff:g id="number">%d</xliff:g> URLs</item>
+    </plurals>
 
     <!-- Sound settings screen, setting check box label -->
     <string name="emergency_tone_title">Emergency dialing signal</string>

src/com/android/settings/security/CredentialManagementAppAdapter.java

@@ -179,8 +179,8 @@ public class CredentialManagementAppAdapter extends RecyclerView.Adapter<Recycle
         }
 
         private String getNumberOfUrlsText(Map<Uri, String> urisToAliases) {
-            String url = urisToAliases.size() > 1 ? " URLs" : " URL";
-            return urisToAliases.size() + url;
+            return mContext.getResources().getQuantityString(R.plurals.number_of_urls,
+                    urisToAliases.size(), urisToAliases.size());
         }
     }