GRPC mTLS request: Problem with client certificates being returned empty

### Expected behavior

Client certificates should be populated with correct certificates provided in config
Log file with detailed flow has been attached

### Actual behavior

javax.net.ssl|ALL|E2|grpc-nio-worker-ELG-1-4|2024-07-09 15:04:40.685 IST|X509Authentication.java:249|No X.509 cert selected for RSA
javax.net.ssl|WARNING|E2|grpc-nio-worker-ELG-1-4|2024-07-09 15:04:40.685 IST|CertificateMessage.java:1084|Unavailable authentication scheme: rsa_pkcs1_sha384
javax.net.ssl|ALL|E2|grpc-nio-worker-ELG-1-4|2024-07-09 15:04:40.685 IST|X509Authentication.java:249|No X.509 cert selected for RSA
javax.net.ssl|WARNING|E2|grpc-nio-worker-ELG-1-4|2024-07-09 15:04:40.686 IST|CertificateMessage.java:1084|Unavailable authentication scheme: rsa_pkcs1_sha512
javax.net.ssl|WARNING|E2|grpc-nio-worker-ELG-1-4|2024-07-09 15:04:40.686 IST|CertificateMessage.java:1094|No available authentication scheme
javax.net.ssl|DEBUG|E2|grpc-nio-worker-ELG-1-4|2024-07-09 15:04:40.686 IST|CertificateMessage.java:1106|No available client authentication scheme
javax.net.ssl|DEBUG|E2|grpc-nio-worker-ELG-1-4|2024-07-09 15:04:40.686 IST|CertificateMessage.java:1140|Produced client Certificate message (
"Certificate": {
"certificate_request_context": "",
"certificate_list": [
]
}
)
[consolelogJmeter.txt](https://github.com/user-attachments/files/16155471/consolelogJmeter.txt)

### Steps to reproduce the problem

1. Configure a grpc request sampler config
2. System.properties are configured for keystore and trustore config as per documentation.
3. Launch jmeter
In jmeter.log keystore is created OK
2024-07-09 15:04:39,608 INFO o.a.j.c.KeystoreConfig: Configuring Keystore with (preload: 'True', startIndex: 0, endIndex: 1, clientCertAliasVarName: 'certAlias')
2024-07-09 15:04:39,609 INFO o.a.j.u.JsseSSLManager: Using default SSL protocol: TLS
2024-07-09 15:04:39,609 INFO o.a.j.u.JsseSSLManager: SSL session context: per-thread
2024-07-09 15:04:39,609 DEBUG o.a.j.u.JsseSSLManager: ssl Provider = null
2024-07-09 15:04:39,610 DEBUG o.a.j.u.JsseSSLManager: SSL stuff all set
2024-07-09 15:04:39,610 DEBUG o.a.j.u.JsseSSLManager: JsseSSLManager installed
2024-07-09 15:04:39,610 INFO o.a.j.u.SSLManager: JmeterKeyStore Location: /home/ebjjssh/newcert3jul/keys/client.jks type JKS
2024-07-09 15:04:39,613 INFO o.a.j.u.SSLManager: KeyStore created OK

4. Jmeter console logs show client certificates as empty while keystore and trustore config correct.
javax.net.ssl|WARNING|E2|grpc-nio-worker-ELG-1-4|2024-07-09 15:04:40.685 IST|CertificateMessage.java:1084|Unavailable authentication scheme: rsa_pkcs1_sha384
javax.net.ssl|ALL|E2|grpc-nio-worker-ELG-1-4|2024-07-09 15:04:40.685 IST|X509Authentication.java:249|No X.509 cert selected for RSA
javax.net.ssl|WARNING|E2|grpc-nio-worker-ELG-1-4|2024-07-09 15:04:40.686 IST|CertificateMessage.java:1084|Unavailable authentication scheme: rsa_pkcs1_sha512
javax.net.ssl|WARNING|E2|grpc-nio-worker-ELG-1-4|2024-07-09 15:04:40.686 IST|CertificateMessage.java:1094|No available authentication scheme
javax.net.ssl|DEBUG|E2|grpc-nio-worker-ELG-1-4|2024-07-09 15:04:40.686 IST|CertificateMessage.java:1106|No available client authentication scheme
javax.net.ssl|DEBUG|E2|grpc-nio-worker-ELG-1-4|2024-07-09 15:04:40.686 IST|CertificateMessage.java:1140|Produced client Certificate message (
"Certificate": {
"certificate_request_context": "",
"certificate_list": [
]
}
)

[consolelogJmeter.txt](https://github.com/user-attachments/files/16155472/consolelogJmeter.txt)

### JMeter Version

5.6.3

### Java Version

17.0.7

### OS Version

RHEL 8.7