Rename attribute to horizontal_divider_visibility

app/src/main/res/layout-v21/task_adapter_row_simple.xml

@@ -18,7 +18,7 @@
 
   <View
     style="@style/horizontal_divider"
-    android:visibility="?attr/horizontal_divider"
+    android:visibility="?attr/horizontal_divider_visibility"
     android:layout_gravity="bottom" />
 
 </com.google.android.material.card.MaterialCardView>

app/src/main/res/values/attrs.xml

@@ -8,7 +8,7 @@
   <!-- theme attributes -->
   <attr format="reference" name="overlay_theme"/>
   <attr format="dimension" name="card_elevation"/>
-  <attr format="integer" name="horizontal_divider"/>
+  <attr format="integer" name="horizontal_divider_visibility"/>
   <attr format="color" name="colorOnPrimaryHint"/>
 
   <declare-styleable name="TimePreference">

app/src/main/res/values/theme.xml

@@ -24,7 +24,7 @@
     <item name="nnf_save_icon_color">?attr/colorAccent</item>
     <item name="nnf_dir_icon_color">?attr/colorAccent</item>
     <item name="card_elevation">2dp</item>
-    <item name="horizontal_divider">2</item> <!-- View.GONE -->
+    <item name="horizontal_divider_visibility">2</item> <!-- View.GONE -->
     <item name="mdtp_theme_dark">@bool/is_dark</item>
   </style>
 
@@ -43,7 +43,7 @@
   <style name="ThemeBlack" parent="Tasks">
     <item name="android:windowBackground">@android:color/black</item>
     <item name="android:colorBackground">@android:color/black</item>
-    <item name="horizontal_divider">0</item> <!-- View.VISIBLE -->
+    <item name="horizontal_divider_visibility">0</item> <!-- View.VISIBLE -->
   </style>
 
   <style name="Wallpaper" parent="Tasks">