Use IntDef for polling frame types

Bug: b/321800939
Test: tested with CTS
Change-Id: I8d8e3dc41e80f09d6107aa5c7883f569fae9fad8
diff --git a/nfc/api/current.txt b/nfc/api/current.txt
index 0383276..e244520 100644
--- a/nfc/api/current.txt
+++ b/nfc/api/current.txt
@@ -232,12 +232,6 @@
     method public final void sendResponseApdu(byte[]);
     field public static final int DEACTIVATION_DESELECTED = 1; // 0x1
     field public static final int DEACTIVATION_LINK_LOSS = 0; // 0x0
-    field @FlaggedApi("android.nfc.nfc_read_polling_loop") public static final char POLLING_LOOP_TYPE_A = 65; // 0x0041 'A'
-    field @FlaggedApi("android.nfc.nfc_read_polling_loop") public static final char POLLING_LOOP_TYPE_B = 66; // 0x0042 'B'
-    field @FlaggedApi("android.nfc.nfc_read_polling_loop") public static final char POLLING_LOOP_TYPE_F = 70; // 0x0046 'F'
-    field @FlaggedApi("android.nfc.nfc_read_polling_loop") public static final char POLLING_LOOP_TYPE_OFF = 88; // 0x0058 'X'
-    field @FlaggedApi("android.nfc.nfc_read_polling_loop") public static final char POLLING_LOOP_TYPE_ON = 79; // 0x004f 'O'
-    field @FlaggedApi("android.nfc.nfc_read_polling_loop") public static final char POLLING_LOOP_TYPE_UNKNOWN = 85; // 0x0055 'U'
     field public static final String SERVICE_INTERFACE = "android.nfc.cardemulation.action.HOST_APDU_SERVICE";
     field public static final String SERVICE_META_DATA = "android.nfc.cardemulation.host_apdu_service";
   }
@@ -271,14 +265,20 @@
   }
 
   @FlaggedApi("android.nfc.nfc_read_polling_loop") public final class PollingFrame implements android.os.Parcelable {
-    ctor public PollingFrame(char, @Nullable byte[], int, int);
+    ctor public PollingFrame(int, @Nullable byte[], int, int);
     method public int describeContents();
     method @NonNull public byte[] getData();
     method public int getGain();
     method public int getTimestamp();
-    method public char getType();
+    method public int getType();
     method public void writeToParcel(@NonNull android.os.Parcel, int);
     field @NonNull public static final android.os.Parcelable.Creator<android.nfc.cardemulation.PollingFrame> CREATOR;
+    field @FlaggedApi("android.nfc.nfc_read_polling_loop") public static final int POLLING_LOOP_TYPE_A = 65; // 0x41
+    field @FlaggedApi("android.nfc.nfc_read_polling_loop") public static final int POLLING_LOOP_TYPE_B = 66; // 0x42
+    field @FlaggedApi("android.nfc.nfc_read_polling_loop") public static final int POLLING_LOOP_TYPE_F = 70; // 0x46
+    field @FlaggedApi("android.nfc.nfc_read_polling_loop") public static final int POLLING_LOOP_TYPE_OFF = 88; // 0x58
+    field @FlaggedApi("android.nfc.nfc_read_polling_loop") public static final int POLLING_LOOP_TYPE_ON = 79; // 0x4f
+    field @FlaggedApi("android.nfc.nfc_read_polling_loop") public static final int POLLING_LOOP_TYPE_UNKNOWN = 85; // 0x55
   }
 
 }