It looks like you're missing the gateway path segment in the actual command:
'https://10.224.155.25:9443/Vamshi/webhdfs/v1/?op=LISTSTATUS'
should be
'https://10.224.155.25:9443/gateway/Vamshi/webhdfs/v1/?op=LISTSTATUS'
And have you intentionally configured the gateway port to 9443 (vs the default 8443)?