Do not reset anonymous identity for PEAP

Bug: 37492360
Test: compile, integration test
Change-Id: I9db7f7dfb7c78ab3dcb2261624f8caa01c457230
diff --git a/service/java/com/android/server/wifi/WifiConfigManager.java b/service/java/com/android/server/wifi/WifiConfigManager.java
index d9f3c1a..9020b8e 100644
--- a/service/java/com/android/server/wifi/WifiConfigManager.java
+++ b/service/java/com/android/server/wifi/WifiConfigManager.java
@@ -2334,7 +2334,9 @@
                 String currentIdentity = TelephonyUtil.getSimIdentity(mTelephonyManager, config);
                 // Update the loaded config
                 config.enterpriseConfig.setIdentity(currentIdentity);
-                config.enterpriseConfig.setAnonymousIdentity("");
+                if (config.enterpriseConfig.getEapMethod() != WifiEnterpriseConfig.Eap.PEAP) {
+                    config.enterpriseConfig.setAnonymousIdentity("");
+                }
             }
         }
     }