Fix forget button on wifi details page.

- Corrected logic for forgetting the current network in the network
details page
- After a user has forgotten a network, the button becomes disabled
(TODO final UX on this - go/remaining-wifi-picker-work tracks this)
- Added unit tests for forgetting network flow
- Fixed bug where the current tethering WifiConfiguration was associated
with the currrent network

Bug: 36458941
Test: m RunSettingsRoboTests
Change-Id: Ie3c4bae8b295908b17179e60359c8bc599519744

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

@@ -84,8 +84,6 @@ public class WifiDetailPreferenceControllerTest {
         MockitoAnnotations.initMocks(this);
 
         mLifecycle = new Lifecycle();
-        mController = new WifiDetailPreferenceController(
-                mockAccessPoint, mContext, mLifecycle, mockWifiManager);
 
         when(mockAccessPoint.getConfig()).thenReturn(mockWifiConfig);
         when(mockAccessPoint.getLevel()).thenReturn(LEVEL);
@@ -93,11 +91,13 @@ public class WifiDetailPreferenceControllerTest {
         when(mockAccessPoint.getRssi()).thenReturn(RSSI);
         when(mockAccessPoint.getSecurityString(false)).thenReturn(SECURITY);
 
+        mController = new WifiDetailPreferenceController(
+                mockAccessPoint, mContext, mLifecycle, mockWifiManager);
+
         setupMockedPreferenceScreen();
 
-        when (mockWifiInfo.getRssi()).thenReturn(RSSI);
+        when(mockWifiInfo.getRssi()).thenReturn(RSSI);
         when(mockWifiManager.getConnectionInfo()).thenReturn(mockWifiInfo);
-        when(mockWifiManager.getWifiApConfiguration()).thenReturn(mockWifiConfig);
     }
 
     private void setupMockedPreferenceScreen() {
@@ -139,7 +139,6 @@ public class WifiDetailPreferenceControllerTest {
         mController.onResume();
 
         verify(mockWifiManager).getConnectionInfo();
-        verify(mockWifiManager).getWifiApConfiguration();
     }
 
     @Test
@@ -178,4 +177,29 @@ public class WifiDetailPreferenceControllerTest {
 
         verify(mockSignalStrengthPref).setDetailText(expectedStrength);
     }
+
+    @Test
+    public void forgetNetwork_ephemeral() {
+        WifiConfiguration wifiConfiguration = new WifiConfiguration();
+        wifiConfiguration.SSID = "ssid";
+        // WifiConfiguration#isEphemeral will not be visible in robolectric until O is supported
+        wifiConfiguration.ephemeral = true;
+        when(mockAccessPoint.getConfig()).thenReturn(wifiConfiguration);
+
+        mController = new WifiDetailPreferenceController(
+                mockAccessPoint, mContext, mLifecycle, mockWifiManager);
+
+        mController.forgetNetwork();
+
+        verify(mockWifiManager).disableEphemeralNetwork(wifiConfiguration.SSID);
+    }
+
+    @Test
+    public void forgetNetwork_saved() {
+        mockWifiConfig.networkId = 5;
+
+        mController.forgetNetwork();
+
+        verify(mockWifiManager).forget(mockWifiConfig.networkId, null);
+    }
 }