modify `flux create secret tls` to create secrets of type TLS

Signed-off-by: Sanskar Jaiswal <jaiswalsanskar078@gmail.com>

cmd/flux/testdata/create_secret/tls/secret-tls.yaml

@@ -102,3 +102,4 @@ stringData:
     XBQO4ig7vY8+1+L3w2xpTN95/rXAvB4BbO/DLea9ArikePoSJ+bVTj0YwrKBghep
     kOvbvVANrpsunlSAcpXm1qkV+G+xPnyJ
     -----END PRIVATE KEY-----
+type: kubernetes.io/tls

pkg/manifestgen/sourcesecret/sourcesecret.go

@@ -163,6 +163,7 @@ func buildSecret(keypair *ssh.KeyPair, hostKey, dockerCfg []byte, options Option
 	}
 
 	if len(options.TLSCrt) != 0 && len(options.TLSKey) != 0 {
+		secret.Type = corev1.SecretTypeTLS
 		secret.StringData[TLSCrtSecretKey] = string(options.TLSCrt)
 		secret.StringData[TLSKeySecretKey] = string(options.TLSKey)
 	} else if len(options.CertFile) != 0 && len(options.KeyFile) != 0 {