Show a "placeholder-ui" when cold starting the app.

app/src/main/AndroidManifest.xml

@@ -20,7 +20,9 @@
         android:supportsRtl="true"
         android:theme="@style/Theme.Phonograph.Light"
         tools:ignore="UnusedAttribute">
-        <activity android:name=".ui.activities.MainActivity">
+        <activity
+            android:name=".ui.activities.MainActivity"
+            android:theme="@style/Theme.Phonograph.Light.MaterialColdStart">
             <intent-filter>
                 <action android:name="android.intent.action.MAIN" />
                 <action android:name="android.intent.action.MUSIC_PLAYER" />

app/src/main/res/values/styles.xml

@@ -40,4 +40,9 @@
         <item name="android:transitionName" tools:ignore="NewApi">toolbar</item>
     </style>
 
+    <style name="Theme.Phonograph.Light.MaterialColdStart" parent="Theme.Phonograph.Light">
+        <item name="android:windowBackground">@drawable/window_background_statusbar_toolbar_tab
+        </item>
+    </style>
+
 </resources>