feat: 优化代码

app/src/main/java/io/legado/app/ui/book/read/ReadBookActivity.kt

@@ -516,7 +516,6 @@ class ReadBookActivity : VMBaseActivity<ReadBookViewModel>(R.layout.activity_boo
         }
         observeEvent<Boolean>(EventBus.UP_CONFIG) {
             upSystemUiVisibility()
-            content_view.upStyle()
             page_view.upBg()
             page_view.upStyle()
             ChapterProvider.upStyle(ReadBookConfig.durConfig)

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

@@ -4,12 +4,6 @@
     android:layout_height="match_parent"
     android:orientation="vertical">
 
-    <io.legado.app.ui.book.read.page.ContentView
-        android:id="@+id/content_view"
-        android:layout_width="match_parent"
-        android:layout_height="match_parent"
-        android:visibility="invisible" />
-
     <io.legado.app.ui.book.read.page.PageView
         android:id="@+id/page_view"
         android:layout_width="match_parent"