Unify media box page title style

reader/src/main/res/layout/view_media_box_header.xml

@@ -9,12 +9,11 @@
 
     <TextView
         android:id="@+id/tv_mediaBoxHeader_title"
-        style="@style/Base.TextAppearance.Widget.AppCompat.Toolbar.Subtitle"
+        style="@style/MediaBoxPageTitleStyle"
         android:layout_width="wrap_content"
         android:layout_height="wrap_content"
         android:layout_marginLeft="16dp"
         android:layout_marginStart="16dp"
-        android:textColor="#de000000"
         android:text="Text"
         app:layout_constraintTop_toTopOf="parent"
         app:layout_constraintBottom_toBottomOf="parent"

reader/src/main/res/layout/view_media_box_tab_signature.xml

@@ -9,15 +9,13 @@
 
     <TextView
         android:id="@+id/tv_title_signature"
+        style="@style/MediaBoxPageTitleStyle"
         android:layout_width="match_parent"
         android:layout_height="56dp"
         android:layout_marginLeft="16dp"
         android:layout_marginStart="16dp"
         android:layout_marginRight="16dp"
         android:layout_marginEnd="16dp"
-        android:gravity="center_vertical"
-        android:textColor="#de000000"
-        android:textSize="14sp"
         android:text="@string/reader_mediaBox_signature_title" />
 
     <TextView

reader/src/main/res/values/styles_media_box.xml

@@ -1,5 +1,10 @@
 <?xml version="1.0" encoding="utf-8"?>
 <resources>
+    <style name="MediaBoxPageTitleStyle">
+        <item name="android:textSize">14sp</item>
+        <item name="android:textColor">#de000000</item>
+        <item name="android:gravity">center_vertical</item>
+    </style>
     <style name="MediaBoxStyle">
         <item name="android:background">@drawable/shape_rec_w_up_rcorner</item>
     </style>