Default MAC address should display "Not Available" in network details

For saved networks that do not have a MAC address available in their
WifiConfiguration such as Passpoint networks, the MAC address will
be the default value of 20:00:00:00:00:00. In this case, display
"Not Available" as the summary of the MAC address preference.

Bug: 137282522
Test: atest WifiDetailPreferenceControllerTest &&
manual - open saved passpoint network details while disconnected
but in range and observe MAC address preference.

Change-Id: Ie9010b0430726de8105852ae2afe10047dcc3676
diff --git a/src/com/android/settings/wifi/details/WifiDetailPreferenceController.java b/src/com/android/settings/wifi/details/WifiDetailPreferenceController.java
index 5e49b2e..a915766 100644
--- a/src/com/android/settings/wifi/details/WifiDetailPreferenceController.java
+++ b/src/com/android/settings/wifi/details/WifiDetailPreferenceController.java
@@ -682,7 +682,11 @@
         }
 
         mMacAddressPref.setVisible(true);
-        mMacAddressPref.setSummary(macAddress);
+        if (macAddress.equals(WifiInfo.DEFAULT_MAC_ADDRESS)) {
+            mMacAddressPref.setSummary(R.string.device_info_not_available);
+        } else {
+            mMacAddressPref.setSummary(macAddress);
+        }
     }
 
     private String getMacAddress() {
diff --git a/tests/robotests/src/com/android/settings/wifi/details/WifiDetailPreferenceControllerTest.java b/tests/robotests/src/com/android/settings/wifi/details/WifiDetailPreferenceControllerTest.java
index 9a1dd4c..010fb74 100644
--- a/tests/robotests/src/com/android/settings/wifi/details/WifiDetailPreferenceControllerTest.java
+++ b/tests/robotests/src/com/android/settings/wifi/details/WifiDetailPreferenceControllerTest.java
@@ -114,7 +114,7 @@
     private static final int TX_LINK_SPEED = 123;
     private static final int RX_LINK_SPEED = 54;
     private static final String SSID = "ssid";
-    private static final String MAC_ADDRESS = WifiInfo.DEFAULT_MAC_ADDRESS;
+    private static final String MAC_ADDRESS = "01:23:45:67:89:ab";
     private static final String RANDOMIZED_MAC_ADDRESS = "RANDOMIZED_MAC_ADDRESS";
     private static final String FACTORY_MAC_ADDRESS = "FACTORY_MAC_ADDRESS";
     private static final String SECURITY = "None";