[Wi-Fi] Can't change EAP method for a saved enterprise Wi-Fi network

Should only allow saved network UI initialization for once.

Bug: 140362368
Test: WifiConfigControllerTest
      manual:
      Manually change EAP method and other security fields for a saved
      Wi-Fi neterprise network.

Change-Id: Iddc1dae53849760f43b41b75262358dff6ba09af

src/com/android/settings/wifi/WifiConfigController.java

@@ -986,7 +986,10 @@ public class WifiConfigController implements TextWatcher,
         }
         mView.findViewById(R.id.eap).setVisibility(View.VISIBLE);
 
+        // TODO (b/140541213): Maybe we can remove initiateEnterpriseNetworkUi by moving code block
+        boolean initiateEnterpriseNetworkUi = false;
         if (mEapMethodSpinner == null) {
+            initiateEnterpriseNetworkUi = true;
             mEapMethodSpinner = (Spinner) mView.findViewById(R.id.method);
             mEapMethodSpinner.setOnItemSelectedListener(this);
             mPhase2Spinner = (Spinner) mView.findViewById(R.id.phase2);
@@ -1043,7 +1046,7 @@ public class WifiConfigController implements TextWatcher,
         }
 
         // Modifying an existing network
-        if (mAccessPoint != null && mAccessPoint.isSaved()) {
+        if (initiateEnterpriseNetworkUi && mAccessPoint != null && mAccessPoint.isSaved()) {
             WifiEnterpriseConfig enterpriseConfig = mAccessPoint.getConfig().enterpriseConfig;
             int eapMethod = enterpriseConfig.getEapMethod();
             int phase2Method = enterpriseConfig.getPhase2Method();