nfc(api): Use settings key and feature string since the API is @hide

Temporary change for creating framework-nfc.jar, need to formalize the
API.

Bug: 303286040
Test: Compiles
(cherry picked from https://googleplex-android-review.googlesource.com/q/commit:34eab749beb70d56cf87da73426240586ebc1ec3)
Merged-In: Iecbf1b58ee2305c509da9c90cd421ee0cb91d379
Change-Id: Iecbf1b58ee2305c509da9c90cd421ee0cb91d379

core/java/android/nfc/Constants.java

+/*
+ * Copyright (C) 2023 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package android.nfc;
+
+/**
+ * @hide
+ * TODO(b/303286040): Holds @hide API constants. Formalize these APIs.
+ */
+public final class Constants {
+    private Constants() { }
+
+    public static final String SETTINGS_SECURE_NFC_PAYMENT_FOREGROUND = "nfc_payment_foreground";
+    public static final String SETTINGS_SECURE_NFC_PAYMENT_DEFAULT_COMPONENT = "nfc_payment_default_component";
+    public static final String FEATURE_NFC_ANY = "android.hardware.nfc.any";
+}

core/java/android/nfc/cardemulation/CardEmulation.java

@@ -26,6 +26,7 @@ import android.content.ComponentName;
 import android.content.Context;
 import android.content.Intent;
 import android.content.pm.PackageManager;
+import android.nfc.Constants;
 import android.nfc.INfcCardEmulation;
 import android.nfc.NfcAdapter;
 import android.os.RemoteException;
@@ -274,7 +275,7 @@ public final class CardEmulation {
             try {
                 preferForeground = Settings.Secure.getInt(
                         contextAsUser.getContentResolver(),
-                        Settings.Secure.NFC_PAYMENT_FOREGROUND) != 0;
+                        Constants.SETTINGS_SECURE_NFC_PAYMENT_FOREGROUND) != 0;
             } catch (SettingNotFoundException e) {
             }
             return preferForeground;