Update Mobile Settings Dialog theme to adopt Dark theme

Bug: 177967771
Test: visual
Change-Id: I2ea908b927d6f87930a2560ca21fab10640f8b65
diff --git a/AndroidManifest.xml b/AndroidManifest.xml
index 8b3160f..c40c3c1 100644
--- a/AndroidManifest.xml
+++ b/AndroidManifest.xml
@@ -517,12 +517,12 @@
         <activity android:name=".network.telephony.ToggleSubscriptionDialogActivity"
                   android:exported="false"
                   android:permission="android.permission.WRITE_EMBEDDED_SUBSCRIPTIONS"
-                  android:theme="@style/Transparent" />
+                  android:theme="@*android:style/Theme.DeviceDefault.Dialog.Alert.DayNight" />
 
         <activity android:name=".network.telephony.DeleteEuiccSubscriptionDialogActivity"
                   android:exported="false"
                   android:permission="android.permission.WRITE_EMBEDDED_SUBSCRIPTIONS"
-                  android:theme="@style/Transparent" />
+                  android:theme="@*android:style/Theme.DeviceDefault.Dialog.Alert.DayNight" />
 
         <activity
             android:name="Settings$TetherSettingsActivity"