Replaced custom background with selectableItemBackground

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

@@ -43,7 +43,7 @@
             android:textStyle="bold"
             android:textColor="@color/status_progress"
             android:textSize="24sp"
-            android:background="@drawable/borderless_button_dark"/>
+            android:background="?android:attr/selectableItemBackground"/>
 
         <Button
             android:id="@+id/butIncSpeed"
@@ -57,7 +57,7 @@
             android:textStyle="bold"
             android:textColor="@color/status_progress"
             android:textSize="24sp"
-            android:background="@drawable/borderless_button_dark"/>
+            android:background="?android:attr/selectableItemBackground"/>
 
         <SeekBar
             android:id="@+id/playback_speed"

app/src/play/res/layout/media_router_controller.xml

@@ -17,7 +17,7 @@
         android:layout_alignParentRight="true"
         android:layout_alignParentEnd="true"
         android:contentDescription="@string/mr_controller_play"
-        android:background="?attr/selectableItemBackgroundBorderless"/>
+        android:background="?android:attr/selectableItemBackground"/>
 
     <LinearLayout android:id="@+id/mrc_control_title_container"
         android:orientation="vertical"

core/src/main/res/drawable/borderless_button_dark.xml

@@ -1,18 +0,0 @@
-<?xml version="1.0" encoding="utf-8"?>
-<selector xmlns:android="http://schemas.android.com/apk/res/android">
-    <item android:state_pressed="true">
-        <shape android:shape="rectangle">
-            <solid android:color="@color/selection_background_color_dark" />
-        </shape>
-    </item>
-    <item android:state_focused="true">
-        <shape android:shape="rectangle">
-            <solid android:color="@color/selection_background_color_dark" />
-        </shape>
-    </item>
-    <item>
-        <shape android:shape="rectangle">
-            <solid android:color="@android:color/transparent" />
-        </shape>
-    </item>
-</selector>

core/src/main/res/values-v16/colors.xml

@@ -1,4 +0,0 @@
-<?xml version="1.0" encoding="utf-8"?>
-<resources>
-    <color name="selection_background_color_dark">#484B4D</color>
-</resources>

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

@@ -28,7 +28,6 @@
     <attr name="ic_folder" format="reference"/>
     <attr name="type_audio" format="reference"/>
     <attr name="type_video" format="reference"/>
-    <attr name="borderless_button" format="reference"/>
     <attr name="overlay_drawable" format="reference"/>
     <attr name="dragview_background" format="reference"/>
     <attr name="dragview_float_background" format="reference"/>