[공통][Common] 스플래시 화면 GUI 적용

app/src/main/res/drawable/splash_background.xml

@@ -1,12 +1,12 @@
 <?xml version="1.0" encoding="utf-8"?>
 <layer-list xmlns:android="http://schemas.android.com/apk/res/android">
 
-  <item android:drawable="@android:color/holo_purple"/>
+  <item android:drawable="@android:color/white"/>
 
   <item>
     <bitmap
       android:gravity="center"
-      android:src="@mipmap/ic_launcher_round"/>
+      android:src="@drawable/splash_logo"/>
   </item>
 
 </layer-list>