Typo Error Causes Keypair Resource Policy to Incorrectly Set `max_concurrent_sftp_sessions`

[agatha197]

There is a typo error in the keypair resource policy handling which leads to max_concurrent_sftp_sessions being incorrectly set to the value of max_concurrent_sessions. This issue prevents users from setting a desired value for max_concurrent_sftp_sessions as it gets overridden by the value intended for max_concurrent_sessions.

Steps to reproduce:

1. Set a distinct value for max_concurrent_sessions and max_concurrent_sftp_sessions in the keypair resource policy.
2. Apply the policy and inspect the applied settings.
3. Notice that max_concurrent_sftp_sessions is not set to the intended value but instead matches the value of max_concurrent_sessions.

Expected behavior:
The max_concurrent_sftp_sessions should be independently settable and retain its specified value, separate from max_concurrent_sessions.

Actual behavior:
The max_concurrent_sftp_sessions incorrectly inherits the value of max_concurrent_sessions due to a typo error in the policy handling code.

This issue affects the flexibility and usability of keypair resource policies, particularly for scenarios requiring different limits for SFTP sessions compared to other types of sessions.

JIRA Issue: BA-1042