FAB now properly scales in multiwindowed mode.

As per the material desing spec [1], floating action buttons should be 56dp
in size normally and 40dp on small displays (like in multiwindow mode) while
always maintaing a 24dp image size.

screenshot (mw): http://screen/URJrg1WoQfn
screenshot (normal): http://screen/TUU65D1sSHp

[1]
https://material.io/guidelines/components/buttons-floating-action-button.html#buttons-floating-action-button-floating-action-button

Bug: 67312080
Test: n/a
PiperOrigin-RevId: 171086404
Change-Id: Ib213cf3c94dbb0f0df5b21f23f3022a8f53d80a8
diff --git a/java/com/android/dialer/app/res/layout/dialtacts_activity.xml b/java/com/android/dialer/app/res/layout/dialtacts_activity.xml
index 4c07f1c..1627844 100644
--- a/java/com/android/dialer/app/res/layout/dialtacts_activity.xml
+++ b/java/com/android/dialer/app/res/layout/dialtacts_activity.xml
@@ -41,13 +41,12 @@
 
   <android.support.design.widget.FloatingActionButton
       android:id="@+id/floating_action_button"
-      android:layout_width="@dimen/floating_action_button_width"
-      android:layout_height="@dimen/floating_action_button_height"
+      android:layout_width="wrap_content"
+      android:layout_height="wrap_content"
       android:layout_gravity="center_horizontal|bottom"
       android:layout_marginBottom="@dimen/floating_action_button_margin_bottom"
       android:contentDescription="@string/action_menu_dialpad_button"
       android:src="@drawable/quantum_ic_dialpad_white_24"
-      android:scaleType="center"
       app:elevation="@dimen/floating_action_button_translation_z"
       app:backgroundTint="@color/dialer_secondary_color"/>