Follow theme's cornerRadius for preview cards

Bug: 124071372
Change-Id: I9952b39da1215b5ca78870f3faaf1b5bb6869a2f
diff --git a/res/values/styles.xml b/res/values/styles.xml
index 5ecac90..12269f7 100644
--- a/res/values/styles.xml
+++ b/res/values/styles.xml
@@ -58,14 +58,13 @@
 
 
     <style name="PreviewCard" parent="CardView.Light">
-        <item name="cardCornerRadius">@dimen/preview_card_corner_radius</item>
+        <item name="cardCornerRadius">?android:dialogCornerRadius</item>
         <item name="android:clipChildren">true</item>
         <item name="contentPadding">@dimen/preview_card_padding</item>
         <item name="android:background">@color/primary_color</item>
     </style>
 
     <style name="FullContentPreviewCard" parent="PreviewCard">
-        <item name="cardCornerRadius">@dimen/preview_card_corner_radius</item>
         <item name="android:clipChildren">true</item>
         <item name="contentPadding">0dp</item>
         <item name="android:background">@color/primary_color</item>