Update API Fuzzing image name to use SECURE_ANALYZERS_PREFIX

What does this MR do?

Update the API Fuzzing image name to use SECURE_ANALYZERS_PREFIX. Using this variable is a pattern for the Secure analyzers. It allows offline users to easily change the image registry used by all Secure analyzers with one variable.

The -engine suffix has also been removed to conform with other secure analyzer container image names.

• Use SECURE_ANALYZER_PREFIX
• Remove -engine suffix
• Remove explicit entrypoint setting

Related to #327508 (closed)

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