android: fixed ANR if we lose focus at startup

If we lose focus during startup, we need to unlock the activity mutex before waiting for the focus lifecycle event, otherwise it will never be delivered.

Reproduced using testcontroller with a DualSense controller attached and the "Allow the app to access the USB device?" dialog popped up.

src/core/android/SDL_android.c

@@ -428,6 +428,7 @@ static AAssetManager *asset_manager = NULL;
 static jobject javaAssetManagerRef = 0;
 
 static SDL_Mutex *Android_ActivityMutex = NULL;
+static int Android_ActivityMutexCount = 0;
 static SDL_Mutex *Android_LifecycleMutex = NULL;
 static SDL_Semaphore *Android_LifecycleEventSem = NULL;
 static SDL_AndroidLifecycleEvent Android_LifecycleEvents[SDL_NUM_ANDROID_LIFECYCLE_EVENTS];
@@ -997,6 +998,15 @@ bool Android_WaitLifecycleEvent(SDL_AndroidLifecycleEvent *event, Sint64 timeout
 {
     bool got_event = false;
 
+    int relock_count = 0;
+    Android_LockActivityMutex();
+    while (Android_ActivityMutexCount > 1) {
+        // We came into this function with the activity lock held, we need to unlock so lifecycle events can be dispatched
+        ++relock_count;
+        Android_UnlockActivityMutex();
+    }
+    Android_UnlockActivityMutex();
+
     while (!got_event && SDL_WaitSemaphoreTimeoutNS(Android_LifecycleEventSem, timeoutNS)) {
         SDL_LockMutex(Android_LifecycleMutex);
         {
@@ -1008,16 +1018,23 @@ bool Android_WaitLifecycleEvent(SDL_AndroidLifecycleEvent *event, Sint64 timeout
         }
         SDL_UnlockMutex(Android_LifecycleMutex);
     }
+
+    while (relock_count > 0) {
+        Android_LockActivityMutex();
+        --relock_count;
+    }
     return got_event;
 }
 
 void Android_LockActivityMutex(void)
 {
     SDL_LockMutex(Android_ActivityMutex);
+    ++Android_ActivityMutexCount;
 }
 
 void Android_UnlockActivityMutex(void)
 {
+    --Android_ActivityMutexCount;
     SDL_UnlockMutex(Android_ActivityMutex);
 }