Controller Crashing - repetition of same config causing multi value setting

I have following settings in controller config where validation.frequencyInSeconds is accidentally repeated. This is causing controller to crash as the value is derived as multi value. it will be better to take either last defined value or avoid this crash.

controller.realtime.segment.validation.frequencyInSeconds=300
controller.realtime.segment.validation.frequencyInSeconds=900
controller.broker.resource.validation.frequencyInSeconds=900

Error:

2021/02/18 14:46:44.389 ERROR [StartServiceManagerCommand] [main] Failed to start a Pinot [CONTROLLER] at 39.246 since launch
java.lang.NumberFormatException: For input string: "[300, 900]"
at java.lang.NumberFormatException.forInputString(NumberFormatException.java:65) ~[?:1.8.0_282]
at java.lang.Integer.parseInt(Integer.java:580) ~[?:1.8.0_282]

Reproduce the controller startup with the repeated validation.frequencyInSeconds settings and trace the NumberFormatException showing the value [300, 900]. Determine the intended handling of duplicate settings, then verify that startup no longer crashes when the configuration contains repeated values.

Written by the indexing model from the issue text.