SoftApManager: Start state machine after initializing WifiNative

This otherwise causes a NPE when StateMachine invokes
WifiNative.deregisterWificondDeathHandler().

Bug: 70146335
Test: Unit tests
Test: Manual soft ap toggle.
Change-Id: I86c9429025ce2b926b207ee2e2324b3a7a386697
diff --git a/service/java/com/android/server/wifi/SoftApManager.java b/service/java/com/android/server/wifi/SoftApManager.java
index 429e3c3..b79c901 100644
--- a/service/java/com/android/server/wifi/SoftApManager.java
+++ b/service/java/com/android/server/wifi/SoftApManager.java
@@ -106,8 +106,6 @@
                          WifiApConfigStore wifiApConfigStore,
                          @NonNull SoftApModeConfiguration apConfig,
                          WifiMetrics wifiMetrics) {
-        mStateMachine = new SoftApStateMachine(looper);
-
         mContext = context;
         mWifiNative = wifiNative;
         mCountryCode = countryCode;
@@ -124,6 +122,7 @@
             mApConfig = config;
         }
         mWifiMetrics = wifiMetrics;
+        mStateMachine = new SoftApStateMachine(looper);
     }
 
     /**