Add click animation

Author: timscriptov

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

@@ -10,7 +10,8 @@
         android:layout_height="wrap_content"
         android:layout_marginStart="8dp"
         android:layout_marginTop="8dp"
-        android:layout_marginEnd="8dp">
+        android:layout_marginEnd="8dp"
+        android:background="?android:attr/selectableItemBackground">
 
         <LinearLayout
             android:id="@+id/list_item"

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

@@ -11,6 +11,7 @@
         android:layout_marginStart="8dp"
         android:layout_marginTop="8dp"
         android:layout_marginEnd="8dp"
+        android:background="?android:attr/selectableItemBackground"
         android:orientation="horizontal"
         tools:ignore="UselessParent">