Material design layout tweaks

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

@@ -1,6 +1,5 @@
 <?xml version="1.0" encoding="utf-8"?>
 <LinearLayout 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="match_parent"
@@ -31,16 +30,13 @@
     <LinearLayout
         android:layout_width="match_parent"
         android:layout_height="match_parent"
-        android:orientation="vertical">
+        android:orientation="vertical"
+        android:padding="16dp">
 
         <LinearLayout
             android:layout_width="match_parent"
             android:layout_height="wrap_content"
-            android:layout_marginLeft="16dp"
-            android:layout_marginTop="16dp"
-            android:layout_marginRight="16dp"
-            android:layout_marginBottom="16dp"
-            android:gravity="center_horizontal|center_vertical"
+            android:gravity="center_vertical"
             android:orientation="horizontal">
 
             <TextView
@@ -48,16 +44,18 @@
                 android:layout_width="wrap_content"
                 android:layout_height="wrap_content"
                 android:text="@string/widget_opacity"
-                android:textSize="18sp"
-                android:textStyle="bold" />
+                android:textSize="16sp"
+                android:textColor="?android:attr/textColorPrimary" />
 
             <TextView
                 android:id="@+id/widget_opacity_textView"
-                android:layout_width="match_parent"
+                android:layout_width="0dp"
                 android:layout_height="wrap_content"
+                android:layout_weight="1"
                 android:gravity="end"
                 android:text="100%"
-                android:textSize="18sp" />
+                android:textSize="16sp"
+                android:textColor="?android:attr/textColorSecondary" />
 
         </LinearLayout>
 
@@ -75,7 +73,6 @@
             android:layout_width="match_parent"
             android:layout_height="wrap_content"
             android:layout_gravity="center"
-            android:layout_margin="16dp"
             android:onClick="confirmCreateWidget"
             android:text="@string/widget_create_button" />
 

core/src/main/res/layout/player_widget.xml

@@ -38,6 +38,7 @@
                 android:id="@+id/imgvCover"
                 android:layout_width="@android:dimen/app_icon_size"
                 android:layout_height="match_parent"
+                android:src="@drawable/ic_antenna"
                 android:layout_margin="12dp" />
 
             <LinearLayout