Use getTitle() for AccessPoint display name

Instead of getSsidStr(), AccessPoint display names should use
getTitle() to accomodate Passpoint networks which use a provider
name instead of a single ssid. This change allows the provider
name to be displayed in the network details page, the long
press wifi dialog, and the config editing dialog.

Bug: 118705403
Test: atest WifiSettingsTest
Change-Id: I930d6218c7e464ad20c0c61130e0cb9ce315d9a2

tests/robotests/src/com/android/settings/wifi/details/WifiDetailPreferenceControllerTest.java

@@ -384,9 +384,9 @@ public class WifiDetailPreferenceControllerTest {
     }
 
     @Test
-    public void entityHeader_shouldHaveLabelSetToSsid() {
-        String label = "ssid";
-        when(mockAccessPoint.getSsidStr()).thenReturn(label);
+    public void entityHeader_shouldHaveLabelSetToTitle() {
+        String label = "title";
+        when(mockAccessPoint.getTitle()).thenReturn(label);
 
         displayAndResume();