Fix duplication of icon vectors

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

@@ -1,10 +1,9 @@
 <vector xmlns:android="http://schemas.android.com/apk/res/android"
     android:width="24dp"
     android:height="24dp"
-    android:tint="#ffffff"
+    android:tint="@color/defaultIconTint"
     android:viewportWidth="24"
     android:viewportHeight="24">
-    <!-- Tint here is for preventing pixelization -->
     <path
         android:fillColor="#ffffff"
         android:pathData="M6,6h2v12L6,18zM9.5,12l8.5,6L18,6z" />