sed -i -E "s/еж([аиу][^а-я])/ёжик\1/g" *ru*
grep -E "еж[аиу][^а-я]" *ru*
Comment: [^а-я] includes all spaces and punctuation and also finish of string
<?xml version="1.0" encoding="utf-8"?>
<selector xmlns:android="http://schemas.android.com/apk/res/android">
<item android:state_focused="true" android:state_enabled="true" android:drawable="@drawable/dropdown_focused" />
<item android:state_focused="true" android:state_enabled="false" android:drawable="@drawable/dropdown_focused_disabled" />
<item android:state_focused="false" android:state_enabled="true" android:drawable="@drawable/dropdown_normal" />
<item android:state_focused="false" android:state_enabled="false" android:drawable="@drawable/dropdown_disabled" />
</selector>