docs(kubernetes examples): updated the curl commands

[Rajakavitha1]

Why

Issues

We need alternative for SeldonCLI

Motivation

gave the curl alternative

What

Summary of changes

Checklist

• Added/updated unit tests
• [*] Added/updated documentation
• Checked for typos in variable names, comments, etc.
• Added licences for new files

Testing

[CLAassistant]

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[paulb-seldon]

LGTM