Make panel support dark mode

Slightly adjust Panel related theme/styles to support dark mode.

Screenshot:
Wifi Panel: https://screenshot.googleplex.com/5FJ1wwMjgrn.png
NFC Panel: https://screenshot.googleplex.com/AhNJhEMXCS7.png
Volume Panel: https://screenshot.googleplex.com/iyOxAz9NJPv.png
Connectivity Panel: https://screenshot.googleplex.com/pvExHZVNW7m.png

Test: Visual/Manual verification
Fixes: 130815366
Change-Id: Ic96898091c52ccebf4437d96099ad553884d1eb4
diff --git a/AndroidManifest.xml b/AndroidManifest.xml
index 8fd0769..5149b9c 100644
--- a/AndroidManifest.xml
+++ b/AndroidManifest.xml
@@ -3097,7 +3097,7 @@
 
         <activity android:name=".panel.SettingsPanelActivity"
             android:label="@string/settings_panel_title"
-            android:theme="@style/Theme.BottomDialog"
+            android:theme="@style/Theme.Panel"
             android:documentLaunchMode="always"
             android:excludeFromRecents="true"
             android:exported="true">
diff --git a/res/layout/panel_layout.xml b/res/layout/panel_layout.xml
index c697afc..abe8f41 100644
--- a/res/layout/panel_layout.xml
+++ b/res/layout/panel_layout.xml
@@ -34,7 +34,7 @@
             android:gravity="center"
             android:paddingBottom="24dp"
             android:paddingTop="18dp"
-            android:textColor="?android:attr/colorPrimary"
+            android:textColor="?android:attr/textColorPrimary"
             android:textSize="20sp"/>
 
         <include layout="@layout/horizontal_divider"/>
diff --git a/res/values/themes.xml b/res/values/themes.xml
index d29d78b..8268ce1 100644
--- a/res/values/themes.xml
+++ b/res/values/themes.xml
@@ -203,7 +203,7 @@
     </style>
 
     <!-- Note that Dialog themes do not set list dividers -->
-    <style name="Theme.BottomDialog" parent="@*android:style/Theme.DeviceDefault.Settings.Dialog">
+    <style name="Theme.Panel" parent="@*android:style/Theme.DeviceDefault.Settings.Dialog">
         <item name="android:windowBackground">@null</item>
         <item name="android:dividerHorizontal">@*android:drawable/list_divider_material</item>
         <item name="android:windowNoTitle">true</item>