[Wi-Fi NetworkRequest] Set theme for the NetworkRequest dialog

We should set the same theme which applied in Settings APP to the NetworkRequestDialog

Bug: 139294487
Test: check if the right theme is applied when launching this activity.
Change-Id: Iefdfd5b810f5cf22c220830e1ee965113a439a3e

AndroidManifest.xml

@@ -2725,7 +2725,7 @@
 
         <activity
             android:name=".wifi.NetworkRequestDialogActivity"
-            android:theme="@style/Transparent"
+            android:theme="@style/Theme.AlertDialog"
             android:excludeFromRecents="true"
             android:launchMode="singleTop"
             android:taskAffinity=".wifi.NetworkRequestDialogActivity"

tests/robotests/src/com/android/settings/wifi/NetworkRequestDialogActivityTest.java

@@ -17,6 +17,7 @@
 package com.android.settings.wifi;
 
 import static com.google.common.truth.Truth.assertThat;
+
 import static org.mockito.ArgumentMatchers.any;
 import static org.mockito.Mockito.mock;
 import static org.mockito.Mockito.spy;
@@ -27,12 +28,16 @@ import android.content.Context;
 import android.net.wifi.WifiConfiguration;
 import android.net.wifi.WifiManager;
 import android.os.Bundle;
+
 import androidx.annotation.Nullable;
 import androidx.appcompat.app.AlertDialog;
+
+import com.android.settings.R;
 import com.android.settings.testutils.shadow.ShadowAlertDialogCompat;
 import com.android.settings.wifi.NetworkRequestErrorDialogFragment.ERROR_DIALOG_TYPE;
 import com.android.settingslib.wifi.WifiTracker;
 import com.android.settingslib.wifi.WifiTrackerFactory;
+
 import org.junit.Before;
 import org.junit.Test;
 import org.junit.runner.RunWith;
@@ -122,4 +127,12 @@ public class NetworkRequestDialogActivityTest {
 
         verify(mActivity).finish();
     }
+
+    @Test
+    public void launchActivityDialog_shouldApplyAlertDialogTheme() {
+        final NetworkRequestDialogActivity activity = Robolectric
+                .setupActivity(NetworkRequestDialogActivity.class);
+
+        assertThat(activity.getThemeResId()).isEqualTo(R.style.Theme_AlertDialog);
+    }
 }