Update volume control ui for tv

As part of this we introduce a new theme "volume_dialog_theme", which
in the general case is the same as the previously used "qs_theme". Just
for TVs we override the accentColor.

Before: https://hsv.googleplex.com/5706562045739008
After: https://hsv.googleplex.com/5373850558660608

Bug: 162302410
Test: flash on atv device && press +/- on remote
Change-Id: I1151746cf417effbb300c0c11a26b8f75e9d8fb2
diff --git a/packages/SystemUI/res/values/styles.xml b/packages/SystemUI/res/values/styles.xml
index 9e5b94e..ee07e61 100644
--- a/packages/SystemUI/res/values/styles.xml
+++ b/packages/SystemUI/res/values/styles.xml
@@ -387,6 +387,9 @@
         <item name="android:homeAsUpIndicator">@drawable/ic_arrow_back</item>
     </style>
 
+    <!-- Overridden by values-television/styles.xml with tv-specific settings -->
+    <style name="volume_dialog_theme" parent="qs_theme"/>
+
     <style name="systemui_theme_remote_input" parent="@android:style/Theme.DeviceDefault.Light">
         <item name="android:colorAccent">@color/remote_input_accent</item>
     </style>