优化

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

@@ -0,0 +1,10 @@
+<vector xmlns:android="http://schemas.android.com/apk/res/android"
+    android:width="24dp"
+    android:height="24dp"
+    android:viewportWidth="24"
+    android:viewportHeight="24"
+    android:tint="?attr/colorControlNormal">
+  <path
+      android:fillColor="@android:color/white"
+      android:pathData="M14.94,4.66h-4.72l2.36,-2.36zM10.25,19.37h4.66l-2.33,2.33zM6.1,6.27L1.6,17.73h1.84l0.92,-2.45h5.11l0.92,2.45h1.84L7.74,6.27L6.1,6.27zM4.97,13.64l1.94,-5.18 1.94,5.18L4.97,13.64zM15.73,16.14h6.12v1.59h-8.53v-1.29l5.92,-8.56h-5.88v-1.6h8.3v1.26l-5.93,8.6z" />
+</vector>

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

@@ -10,6 +10,36 @@
         android:title="@string/select_folder"
         app:showAsAction="always" />
 
+    <item
+        android:id="@+id/menu_sort"
+        android:title="@string/sort"
+        android:icon="@drawable/ic_sort"
+        app:showAsAction="always">
+
+        <menu>
+
+            <item
+                android:id="@+id/menu_sort_name"
+                android:checkable="true"
+                android:title="@string/sort_by_name"
+                app:showAsAction="never" />
+
+            <item
+                android:id="@+id/menu_sort_size"
+                android:checkable="true"
+                android:title="@string/sort_by_size"
+                app:showAsAction="never" />
+
+            <item
+                android:id="@+id/menu_sort_time"
+                android:checkable="true"
+                android:title="@string/sort_by_time"
+                app:showAsAction="never" />
+
+        </menu>
+
+    </item>
+
     <item
         android:id="@+id/menu_scan_folder"
         android:title="@string/scan_folder"
@@ -20,26 +50,4 @@
         android:title="@string/import_file_name"
         app:showAsAction="never" />
 
-    <group android:id="@+id/menu_group_sort">
-
-        <item
-            android:id="@+id/menu_sort_name"
-            android:checkable="true"
-            android:title="@string/sort_by_name"
-            app:showAsAction="never" />
-
-        <item
-            android:id="@+id/menu_sort_size"
-            android:checkable="true"
-            android:title="@string/sort_by_size"
-            app:showAsAction="never" />
-
-        <item
-            android:id="@+id/menu_sort_time"
-            android:checkable="true"
-            android:title="@string/sort_by_time"
-            app:showAsAction="never" />
-
-    </group>
-
 </menu>