Make VerifyingIndexInput public (#117518)

This way we can verify store files as we read them directly,
without going through a store abstraction we may not have if we
copy lucene files around.

Author: bcully

server/src/main/java/org/elasticsearch/index/store/Store.java

@@ -1217,14 +1217,14 @@ public static String digestToString(long digest) {
      * mechanism that is used in some repository plugins (S3 for example). However, the checksum is only calculated on
      * the first read. All consecutive reads of the same data are not used to calculate the checksum.
      */
-    static class VerifyingIndexInput extends ChecksumIndexInput {
+    public static class VerifyingIndexInput extends ChecksumIndexInput {
         private final IndexInput input;
         private final Checksum digest;
         private final long checksumPosition;
         private final byte[] checksum = new byte[8];
         private long verifiedPosition = 0;
 
-        VerifyingIndexInput(IndexInput input) {
+        public VerifyingIndexInput(IndexInput input) {
             this(input, new BufferedChecksum(new CRC32()));
         }