Go Launcher: Update Overview Actions buttons

This updates the layout of the overview buttons to better match more recent UX mocks. It also restores the buttons' captions, which had gone missing.

Bug: 183448909
Test: Manual (verified on Wembley and Sargo)
Change-Id: I931df92cd0d255289168694d4a950649eec7da75
diff --git a/go/quickstep/res/values/styles.xml b/go/quickstep/res/values/styles.xml
new file mode 100644
index 0000000..927c49a
--- /dev/null
+++ b/go/quickstep/res/values/styles.xml
@@ -0,0 +1,26 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!--
+     Copyright (C) 2021 The Android Open Source Project
+
+     Licensed under the Apache License, Version 2.0 (the "License");
+     you may not use this file except in compliance with the License.
+     You may obtain a copy of the License at
+
+          http://www.apache.org/licenses/LICENSE-2.0
+
+     Unless required by applicable law or agreed to in writing, software
+     distributed under the License is distributed on an "AS IS" BASIS,
+     WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+     See the License for the specific language governing permissions and
+     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>
+</resources>
\ No newline at end of file