Address some Android lint warnings

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

@@ -24,6 +24,7 @@
         android:id="@+id/expand_icon"
         android:layout_width="wrap_content"
         android:layout_height="wrap_content"
-        app:tint="?attr/colorOnBackground" />
+        app:tint="?attr/colorOnBackground"
+        tools:ignore="ContentDescription" />
 
 </LinearLayout>

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

@@ -1,6 +1,7 @@
 <?xml version="1.0" encoding="utf-8"?>
 <FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
     xmlns:app="http://schemas.android.com/apk/res-auto"
+    xmlns:tools="http://schemas.android.com/tools"
     android:layout_width="match_parent"
     android:layout_height="wrap_content"
     android:background="?attr/colorToolbar"
@@ -12,6 +13,7 @@
         android:layout_height="56dp"
         android:layout_gravity="center"
         app:srcCompat="@drawable/ic_tachi"
-        app:tint="?attr/colorOnToolbar" />
+        app:tint="?attr/colorOnToolbar"
+        tools:ignore="ContentDescription" />
 
 </FrameLayout>

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

@@ -49,8 +49,7 @@
         app:layout_constraintEnd_toStartOf="@id/chapter_title"
         app:srcCompat="@drawable/ic_bookmark_24dp"
         app:tint="?attr/colorAccent"
-        tools:visibility="visible"
-         />
+        tools:visibility="visible" />
 
     <TextView
         android:id="@+id/chapter_title"