Add dark theme for Shell app.

Bugreport info dialog is used in the BugreportProgressService; services
are not themeable from the manifest file. Added themed context wrapper
in the service file.

Text view underlines are no longer black, and are white in color.

Bug: 128364209
Test: build and flash to device, manually verified the color of the dialog
Change-Id: Ia42c1c7c2b6f2e30d91a5522f1d6b3507b032cdb
diff --git a/packages/Shell/AndroidManifest.xml b/packages/Shell/AndroidManifest.xml
index e00f204..d9936d6 100644
--- a/packages/Shell/AndroidManifest.xml
+++ b/packages/Shell/AndroidManifest.xml
@@ -205,8 +205,9 @@
     <uses-permission android:name="android.permission.INTERACT_ACROSS_PROFILES"/>
 
     <application android:label="@string/app_label"
-                 android:defaultToDeviceProtectedStorage="true"
-                 android:directBootAware="true">
+                android:theme="@android:style/Theme.DeviceDefault.DayNight"
+                android:defaultToDeviceProtectedStorage="true"
+                android:directBootAware="true">
         <provider
             android:name="androidx.core.content.FileProvider"
             android:authorities="com.android.shell"
@@ -231,7 +232,6 @@
 
         <activity
             android:name=".BugreportWarningActivity"
-            android:theme="@android:style/Theme.DeviceDefault.Light.Dialog.Alert"
             android:finishOnCloseSystemDialogs="true"
             android:excludeFromRecents="true"
             android:exported="false" />