Exposing Configuration Handling for Flow Name Shortening in TimelineUtils

When configuring the maximum size for flow names using yarn.timeline-service.flowname.max-size, users may inadvertently set this parameter to a non-positive value, expecting the system to handle it correctly. However, such misconfigurations lead to the flow name not being shortened, with no indication given to the user about the issue. This can cause confusion as the flow name remains unaltered, despite the expectation that it should be shortened.

Expected Behavior: 
The system should log a warning when an invalid configuration is detected, informing the user that the flow name will not be shortened due to a non-positive value being set for yarn.timeline-service.flowname.max-size.

How-to-Fix:
We propose adding log statements to expose the handling of invalid configuration values when shortening flow names.