HBASE-18016 Changes to inherit default behavior of abort from StateMachineProcedure making TruncateTableProcedure abortable

This will allow abort and manual cleanup of stuck instances of TruncateTableProcedure.

Signed-off-by: Michael Stack <stack@apache.org>

hbase-server/src/main/java/org/apache/hadoop/hbase/master/procedure/TruncateTableProcedure.java

@@ -196,12 +196,6 @@ public class TruncateTableProcedure
     return TableOperationType.EDIT;
   }
 
-  @Override
-  public boolean abort(final MasterProcedureEnv env) {
-    // TODO: We may be able to abort if the procedure is not started yet.
-    return false;
-  }
-
   @Override
   public void toStringClassDetails(StringBuilder sb) {
     sb.append(getClass().getSimpleName());