Fix shared element transition

app/src/main/java/com/hippo/ehviewer/ui/scene/BaseScene.java

@@ -27,6 +27,7 @@ import android.view.Gravity;
 import android.view.LayoutInflater;
 import android.view.View;
 import android.view.ViewGroup;
+import android.view.ViewTreeObserver;
 
 import androidx.annotation.IdRes;
 import androidx.annotation.NonNull;
@@ -198,6 +199,15 @@ public abstract class BaseScene extends SceneFragment {
     @Override
     public void onViewCreated(@NonNull View view, @Nullable Bundle savedInstanceState) {
         super.onViewCreated(view, savedInstanceState);
+        postponeEnterTransition();
+        view.getViewTreeObserver().addOnPreDrawListener(new ViewTreeObserver.OnPreDrawListener() {
+            @Override
+            public boolean onPreDraw() {
+                view.getViewTreeObserver().removeOnPreDrawListener(this);
+                startPostponedEnterTransition();
+                return true;
+            }
+        });
 
         // Update left drawer locked state
         if (needShowLeftDrawer()) {