Update colors.xml

Author: Zenlua

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

@@ -1,4 +1,4 @@
-<?xml version='1.0' encoding='utf-8' ?>
+<?xml version="1.0" encoding="utf-8"?>
 <resources>
     <color name="purple_500">#6200EE</color>
     <color name="purple_700">#3700B3</color>