Update theme for ChannelPanelActivity

- set correct switch style
- update background color

Fixes: 238845212
Test: visual
Change-Id: Iaf54fa5d98f7527543fc02d1108cbafe851bd574
diff --git a/AndroidManifest.xml b/AndroidManifest.xml
index 6fe6832..08fbf04 100644
--- a/AndroidManifest.xml
+++ b/AndroidManifest.xml
@@ -3717,7 +3717,7 @@
         <!-- Show channel-level notification settings (channel passed in as extras) -->
         <activity android:name=".notification.app.ChannelPanelActivity"
                   android:label="@string/notification_channel_title"
-                  android:theme="@style/Theme.Panel"
+                  android:theme="@style/Theme.Panel.Material"
                   android:excludeFromRecents="true"
                   android:configChanges="keyboardHidden|screenSize"
                   android:exported="true">