Make FAB button ripple bounded

Bug: 17411557
Change-Id: I7b9946bf11daa37e9e242019ae2b14463daaa8c5
diff --git a/res/drawable/floating_action_button.xml b/res/drawable/floating_action_button.xml
index e5ae14a..d550190 100644
--- a/res/drawable/floating_action_button.xml
+++ b/res/drawable/floating_action_button.xml
@@ -16,4 +16,10 @@
 -->
 
 <ripple xmlns:android="http://schemas.android.com/apk/res/android"
-    android:color="@color/floating_action_button_touch_tint" />
\ No newline at end of file
+    android:color="@color/floating_action_button_touch_tint">
+    <item android:id="@android:id/mask">
+        <shape android:shape="oval">
+            <solid android:color="@android:color/white" />
+        </shape>
+    </item>
+</ripple>
\ No newline at end of file