清理代码

app/src/main/res/drawable/ic_download_line.xml

@@ -1,4 +0,0 @@
-<?xml version="1.0" encoding="utf-8"?>
-<vector xmlns:android="http://schemas.android.com/apk/res/android" android:width="24dp" android:height="24dp" android:viewportWidth="960" android:viewportHeight="960" android:tint="?attr/colorControlNormal">
-  <path android:fillColor="@android:color/white" android:pathData="M480,640L280,440L336,382L440,486L440,160L520,160L520,486L624,382L680,440L480,640ZM240,800Q207,800 183.5,776.5Q160,753 160,720L160,600L240,600L240,720Q240,720 240,720Q240,720 240,720L720,720Q720,720 720,720Q720,720 720,720L720,600L800,600L800,720Q800,753 776.5,776.5Q753,800 720,800L240,800Z"/>
-</vector>

app/src/main/res/menu/book_read.xml

@@ -19,7 +19,7 @@
 
         <item
             android:id="@+id/menu_download"
-            android:icon="@drawable/ic_download_line"
+            android:icon="@drawable/ic_download"
             android:title="@string/offline_cache"
             app:showAsAction="always" />
 

app/src/main/res/menu/main_bookshelf.xml

@@ -42,7 +42,7 @@
 
     <item
         android:id="@+id/menu_download"
-        android:icon="@drawable/ic_download_line"
+        android:icon="@drawable/ic_download"
         android:title="@string/cache_export"
         app:showAsAction="never" />