Remove redundant colors and use icons

app/src/main/res/mipmap-anydpi-v26/ic_stop.xml

@@ -1,5 +1,5 @@
 <?xml version="1.0" encoding="utf-8"?>
 <adaptive-icon xmlns:android="http://schemas.android.com/apk/res/android">
-    <background android:drawable="@color/ic_stop_background"/>
+    <background android:drawable="@color/white"/>
     <foreground android:drawable="@mipmap/ic_stop_foreground"/>
 </adaptive-icon>