Remove weird cropping from icon when showing missing chapter warning (#4769)

app/src/main/res/layout/reader_transition_view.xml

@@ -23,10 +23,10 @@
         android:gravity="center_vertical">
 
         <ImageView
-            android:layout_width="16dp"
-            android:layout_height="16dp"
+            android:layout_width="18dp"
+            android:layout_height="18dp"
             android:layout_marginEnd="8dp"
-            android:scaleType="center"
+            android:scaleType="fitCenter"
             app:srcCompat="@drawable/ic_warning_white_24dp"
             app:tint="?attr/colorOnBackground"
             tools:ignore="ContentDescription" />