Using FsUtils instead of Files API to extract file extension

hoodie-common/src/main/java/com/uber/hoodie/common/table/timeline/HoodieInstant.java

@@ -18,11 +18,11 @@
 
 import com.google.common.io.Files;
 import com.uber.hoodie.common.table.HoodieTimeline;
+import com.uber.hoodie.common.util.FSUtils;
 import org.apache.hadoop.fs.FileStatus;
 
 import java.io.Serializable;
 import java.util.Objects;
-import java.util.Optional;
 
 /**
  * A Hoodie Instant represents a action done on a hoodie dataset.
@@ -42,11 +42,11 @@ public class HoodieInstant implements Serializable {
     public HoodieInstant(FileStatus fileStatus) {
         // First read the instant timestamp. [==>20170101193025<==].commit
         String fileName = fileStatus.getPath().getName();
-        String fileExtension = Files.getFileExtension(fileName);
-        timestamp = fileName.replace("." + fileExtension, "");
+        String fileExtension = FSUtils.getFileExtension(fileName);
+        timestamp = fileName.replace(fileExtension, "");
 
         // Next read the action for this marker
-        action = fileExtension;
+        action = fileExtension.replaceFirst(".", "");
         if(action.equals("inflight")) {
             // This is to support backwards compatibility on how in-flight commit files were written
             // General rule is inflight extension is .<action>.inflight, but for commit it is .inflight