Fix handling of large ACR lists

If an ACR list was split over multiple responses,
AcrListResponse#getAcrListData used BerTlvData#getData to get the array
extra responses after the first should be copied into. However, since
BerTlvData#getData returned a copy of the array and not the actual
array, the copies had no effect.

Fix by implementing BerTlvData#addData, which copies data to the correct
position and increments the index pointer in one go, and adjust
AcrListResponse#getAcrListData to use it.

Also, remove BerTlvData#setCurrentIndex so that the atomic
BerTlvData#addData must be used instead.

library/src/main/java/pro/javacard/gp/SEAccessControl.java

@@ -602,17 +602,18 @@ public byte[] getData() {
             return Arrays.copyOf(data, data.length);
         }
 
+        public void addData(final byte[] source) {
+            System.arraycopy(source, 0, data, currentIndex, source.length);
+            currentIndex += source.length;
+        }
+
         public int getLength() {
             return length;
         }
 
         public int getCurrentIndex() {
             return currentIndex;
         }
-
-        public void setCurrentIndex(int index) {
-            this.currentIndex = index;
-        }
     }
 
     /*
@@ -662,8 +663,7 @@ public static BerTlvData getAcrListData(final BerTlvData previousData, final byt
                 System.arraycopy(data, offset, berData, 0, data.length - offset);
                 return new BerTlvData(berData, length, data.length - offset);
             } else if (previousData != null) {
-                System.arraycopy(data, 0, previousData.getData(), previousData.currentIndex, data.length);
-                previousData.setCurrentIndex(data.length + previousData.currentIndex);
+                previousData.addData(data);
                 return previousData;
             } else {
                 throw new GPDataException("ACR get data : bad response format (GET_DATA)");