WifiService: Fix build (missing import)

Signed-off-by: San Mehat <san@google.com>
diff --git a/services/java/com/android/server/WifiService.java b/services/java/com/android/server/WifiService.java
index 5cbe7f3..a940af3 100644
--- a/services/java/com/android/server/WifiService.java
+++ b/services/java/com/android/server/WifiService.java
@@ -38,6 +38,7 @@
 import android.net.wifi.WifiStateTracker;
 import android.net.wifi.ScanResult;
 import android.net.wifi.WifiConfiguration;
+import android.net.wifi.SupplicantState;
 import android.net.NetworkStateTracker;
 import android.net.DhcpInfo;
 import android.os.Binder;