nfc(api): Add API to set/get default NFC SubscriptionId

For devices that have UICC/EUICC configured to serve as NFCEE, this API
will return the subscription ID of default NFCEE.

Bug: 321314635
Test: atest CtsNfcTestCases

Change-Id: I9d49c807ffa28653c205855448094435c30b2f02
diff --git a/nfc/api/current.txt b/nfc/api/current.txt
index 7ae2eafa..2aa73db 100644
--- a/nfc/api/current.txt
+++ b/nfc/api/current.txt
@@ -202,6 +202,7 @@
     method public boolean categoryAllowsForegroundPreference(String);
     method @Nullable @RequiresPermission(android.Manifest.permission.NFC_PREFERRED_PAYMENT_INFO) public java.util.List<java.lang.String> getAidsForPreferredPaymentService();
     method public java.util.List<java.lang.String> getAidsForService(android.content.ComponentName, String);
+    method @FlaggedApi("android.nfc.enable_card_emulation_euicc") public int getDefaultNfcSubscriptionId();
     method @Nullable @RequiresPermission(android.Manifest.permission.NFC_PREFERRED_PAYMENT_INFO) public CharSequence getDescriptionForPreferredPaymentService();
     method public static android.nfc.cardemulation.CardEmulation getInstance(android.nfc.NfcAdapter);
     method @Nullable @RequiresPermission(android.Manifest.permission.NFC_PREFERRED_PAYMENT_INFO) public String getRouteDestinationForPreferredPaymentService();