Generating signed apk bug solved(xmlns error)

Author: Abhishek

.idea/misc.xml

@@ -4,7 +4,6 @@
 <!-- CardView helps design a mini layout in the form of cards -->
 <!-- Cards provide an easy way to contain a group of views while providing a consistent style for the container -->
 <android.support.v7.widget.CardView xmlns:android="http://schemas.android.com/apk/res/android"
-    xmlns:app="http://schemas.android.com/tools"
     xmlns:card_view="http://schemas.android.com/apk/res-auto"
     android:layout_width="match_parent"
     android:layout_height="wrap_content"