SoftApManager: Move SoftApManager to WifiStateMachine thread

This was changed to Wifiservice handler thread in ag/1202581. Reverting
back to WifiStateMachine's thread because I think the previous change was
unintentional. SoftApManager should run in the same thread as
WifiStateMachine.

Bug: 70146335
Test: Unit tests.
Test: SoftAp turns on/off.
Test: Will send for regression tests.
Change-Id: Ic2ff28cd6f726b77353f9abacbb451f95fc763ac
(cherry picked from commit 44662bb6fd5327691e44479657bb1396b87ed126)
diff --git a/service/java/com/android/server/wifi/WifiInjector.java b/service/java/com/android/server/wifi/WifiInjector.java
index f6770a5..0ed5b35 100644
--- a/service/java/com/android/server/wifi/WifiInjector.java
+++ b/service/java/com/android/server/wifi/WifiInjector.java
@@ -380,7 +380,7 @@
                                            @NonNull IApInterface apInterface,
                                            @NonNull String ifaceName,
                                            @NonNull SoftApModeConfiguration config) {
-        return new SoftApManager(mContext, mWifiServiceHandlerThread.getLooper(),
+        return new SoftApManager(mContext, mWifiStateMachineHandlerThread.getLooper(),
                                  mWifiNative, mCountryCode.getCountryCode(),
                                  listener, apInterface, ifaceName, nmService,
                                  mWifiApConfigStore, config, mWifiMetrics);