WifiEnterpriseConfiguration: Do not print credentials in toString

BUG:25624963
Change-Id: I939a12a27d6b915d8a9cc8b142f645fba0ee42ec
diff --git a/wifi/java/android/net/wifi/WifiEnterpriseConfig.java b/wifi/java/android/net/wifi/WifiEnterpriseConfig.java
index 59b22bd..16035ad 100644
--- a/wifi/java/android/net/wifi/WifiEnterpriseConfig.java
+++ b/wifi/java/android/net/wifi/WifiEnterpriseConfig.java
@@ -768,7 +768,9 @@
     public String toString() {
         StringBuffer sb = new StringBuffer();
         for (String key : mFields.keySet()) {
-            sb.append(key).append(" ").append(mFields.get(key)).append("\n");
+            // Don't display password in toString().
+            String value = (key == PASSWORD_KEY) ? "<removed>" : mFields.get(key);
+            sb.append(key).append(" ").append(value).append("\n");
         }
         return sb.toString();
     }