add ripple effect to btn

src/main/res/layout/btn_email_login_register.xml

@@ -4,6 +4,7 @@
     xmlns:app="http://schemas.android.com/apk/res-auto"
     android:layout_width="match_parent"
     android:layout_height="@dimen/login_register_btn_height"
+    android:foreground="?attr/selectableItemBackground"
     android:background="@drawable/bg_email_btn"
     >
 

src/main/res/layout/btn_facebook_login_register.xml

@@ -4,6 +4,7 @@
     xmlns:app="http://schemas.android.com/apk/res-auto"
     android:layout_width="match_parent"
     android:layout_height="@dimen/login_register_btn_height"
+    android:foreground="?attr/selectableItemBackground"
     android:background="@drawable/bg_facebook_btn"
     >
 

src/main/res/layout/btn_google_login_register.xml

@@ -4,6 +4,7 @@
     xmlns:app="http://schemas.android.com/apk/res-auto"
     android:layout_width="match_parent"
     android:layout_height="@dimen/login_register_btn_height"
+    android:foreground="?attr/selectableItemBackground"
     android:background="@drawable/bg_google_btn"
     >
 

src/main/res/values/styles.xml

@@ -1,6 +1,7 @@
 <?xml version="1.0" encoding="utf-8"?>
 <resources>
     <style name="EmailLoginRegisterFormSubmitBtn">
+        <item name="android:foreground">?attr/selectableItemBackground</item>
         <item name="android:background">@drawable/bg_email_login_register_form_submit_btn</item>
         <item name="android:textColor">@android:color/white</item>
         <item name="android:textSize">14sp</item>