### Description

We now support storing KNN vectors as part of our indexed data.  These vectors should be included in the disk usage API.
server/src/main/java/org/elasticsearch/action/admin/indices/diskusage/IndexDiskUsageAnalyzer.java
private final Map<Long, BytesReadTracker> slicedTrackers = new HashMap<>();
        @Override
        BytesReadTracker createSliceTracker(long offset) {
            return slicedTrackers.computeIfAbsent(offset, k -> new BytesReadTracker());
        }
        @Override
        void trackPositions(long position, int length) {
            
        }
        @Override
        void resetBytesRead() {
            slicedTrackers.values().forEach(BytesReadTracker::resetBytesRead);
        }
        @Override
        long getBytesRead() {
            return slicedTrackers.values().stream().mapToLong(BytesReadTracker::getBytesRead).sum();
        }
    }
    static long getIndexSize(IndexCommit commit) throws IOException {
        long total = 0;
        for (String file : commit.getFileNames()) {
            total += commit.getDirectory().fileLength(file);
        }
        return total;
    }
    /**
     * Periodically checks if the task was cancelled so the analyzing process can abort quickly.
     */
    private static class CancellationChecker {