Rework NIU Actions buttons UI

The shapes, colors, icons, and layout of the NIU Actions buttons have been updated to match the latest UI specs. The icons also no longer overlap with the layout above them, which solves a picking issue.

Bug: 186004471
Bug: 187460625
Test: Manual (tried on Wembley and Pixel 3A)
Change-Id: Ie7a0ca0c21805fc0f126053ec791fd2460710d33
diff --git a/go/quickstep/res/values/styles.xml b/go/quickstep/res/values/styles.xml
index 927c49a..df49ecd 100644
--- a/go/quickstep/res/values/styles.xml
+++ b/go/quickstep/res/values/styles.xml
@@ -15,12 +15,31 @@
      limitations under the License.
 -->
 <resources>
-    <style name="GoOverviewActionButton"
-        parent="@android:style/Widget.DeviceDefault.Button">
-        <item name="android:textColor">@color/overview_button</item>
-        <item name="android:drawableTint">@color/overview_button</item>
-        <item name="android:tint">?android:attr/textColorPrimary</item>
-        <item name="android:drawablePadding">8dp</item>
-        <item name="android:textAllCaps">false</item>
+    <style name="GoOverviewActionButton">
+        <item name="android:tint">@color/go_overview_button_icon_color</item>
+        <item name="android:backgroundTint">@color/go_overview_button_color</item>
+        <item name="android:background">@drawable/round_rect_button</item>
+        <item name="android:layout_width">@dimen/go_overview_button_width</item>
+        <item name="android:layout_height">@dimen/go_overview_button_height</item>
+        <item name="android:layout_gravity">center_horizontal</item>
+    </style>
+
+    <style name="GoOverviewActionButtonCaption">
+        <item name="android:fontFamily">roboto-medium</item>
+        <item name="android:textSize">14dp</item>
+        <item name="android:textColor">@color/go_overview_button_icon_color</item>
+        <item name="android:lineHeight">20dp</item>
+        <item name="android:textAlignment">center</item>
+        <item name="android:importantForAccessibility">no</item>
+        <item name="android:layout_width">wrap_content</item>
+        <item name="android:layout_height">wrap_content</item>
+        <item name="android:layout_marginTop">@dimen/go_overview_button_caption_margin</item>
+        <item name="android:layout_gravity">center_horizontal</item>
+    </style>
+
+    <style name="GoOverviewActionButtonContainer">
+        <item name="android:layout_width">@dimen/go_overview_button_container_width</item>
+        <item name="android:layout_height">wrap_content</item>
+        <item name="android:orientation">vertical</item>
     </style>
 </resources>
\ No newline at end of file