Bring Widget Picker message style inline with All Apps message style.

Bug: 188227318
Test: Local flash with TestDPC to test message.
Change-Id: I63403f1472a582a63299e647604eaea25b50b8e7
diff --git a/res/layout/widgets_full_sheet.xml b/res/layout/widgets_full_sheet.xml
index e867405..e3f1fca 100644
--- a/res/layout/widgets_full_sheet.xml
+++ b/res/layout/widgets_full_sheet.xml
@@ -38,12 +38,13 @@
             android:background="@drawable/bg_rounded_corner_bottom_sheet_handle"/>
 
         <TextView
+            style="@style/PrimaryHeadline"
             android:id="@+id/no_widgets_text"
             android:layout_width="match_parent"
             android:layout_height="match_parent"
             android:gravity="center"
             android:visibility="gone"
-            android:textSize="20sp"
+            android:textSize="18sp"
             android:layout_below="@id/search_and_recommendations_container"
             tools:text="No widgets available" />