fix(signaling): call startForeground() first in onCreate() to reduce FGS timeout risk (#1100)

Move startForeground() to be the first call after super.onCreate(), before
any SharedPreferences IPC. Under memory pressure (Xiaomi HyperOS), the
SharedPrefs read in getCallbackDispatcher() can block the main thread for
50-500ms, pushing startForeground() past Xiaomi's aggressive ~1.2s window
and causing ForegroundServiceDidNotStartInTimeException.

startForeground() has no dependency on FlutterEngineHelper or callbackHandle —
the engine starts in onStartCommand(), which runs after onCreate() completes.

Author: SERDUN

packages/webtrit_signaling_service/webtrit_signaling_service_android/android/src/main/kotlin/com/webtrit/signaling_service/SignalingForegroundService.kt

@@ -59,14 +59,12 @@ class SignalingForegroundService : Service() {
 
     override fun onCreate() {
         super.onCreate()
-        Log.d(TAG, "SignalingForegroundService onCreate")
+        startForeground()
 
+        Log.d(TAG, "SignalingForegroundService onCreate")
         instance = this
-
         val callbackHandle = StorageDelegate.getCallbackDispatcher(applicationContext)
         flutterEngineHelper = FlutterEngineHelper(applicationContext, callbackHandle, this)
-
-        startForeground()
         isRunning = true
     }