[BUG] Set secret operation of the Key Vault Secrets Client overrides the content type of the secret with application/json

[nagyesta]

Describe the bug
The Key Vault Secrets Client sets or overrides the content type of the secret with application/json. This means, that even if the caller specified the content type of the secret, the created secret in the Key Vault will have application/json persisted.

Exception or Stack Trace
N/A

To Reproduce
Run the following test:

        DefaultAzureCredential credentials = new DefaultAzureCredentialBuilder().build();
        SecretClient secretClient = new SecretClientBuilder().vaultUrl(KEY_VAULT_URL)
                .credential(credentials)
                .buildClient();

        final KeyVaultSecret secretOptions = new KeyVaultSecret("plain-text", LOREM_IPSUM);
        secretOptions.getProperties().setContentType(TEXT_PLAIN);
        KeyVaultSecret result = secretClient.setSecret(secretOptions);

        assertThat(result.getProperties().getContentType()).isEqualTo(TEXT_PLAIN);

Code Snippet
The content type is set in the following locations:

• azure-sdk-for-java/sdk/keyvault/azure-security-keyvault-secrets/src/main/java/com/azure/security/keyvault/secrets/implementation/SecretClientImpl.java

  Line 475 in 18e1933

  parameters.setContentType(contentType);

• azure-sdk-for-java/sdk/keyvault/azure-security-keyvault-secrets/src/main/java/com/azure/security/keyvault/secrets/implementation/SecretClientImpl.java

  Line 622 in 18e1933

  parameters.setContentType(contentType);

The contentType parameter is always getting applciation/json as value due to these lines:

• azure-sdk-for-java/sdk/keyvault/azure-security-keyvault-secrets/src/main/java/com/azure/security/keyvault/secrets/SecretAsyncClient.java

  Line 297 in 3f261df

  secret.getProperties().getTags(), ContentType.APPLICATION_JSON,

• azure-sdk-for-java/sdk/keyvault/azure-security-keyvault-secrets/src/main/java/com/azure/security/keyvault/secrets/SecretClient.java

  Line 268 in 3f261df

  secret.getValue(), secretProperties.getTags(), ContentType.APPLICATION_JSON,

Expected behavior
When the contentType is set in the secret properties object, then it is persisted as-is, the test in the "To Reproduce" section passes.

Screenshots
N/A

Setup (please complete the following information):

• OS: Any
• IDE: Any
• Library/Libraries: com.azure:azure-security-keyvault-secrets:4.7.0
• Java version: Any
• App Server/Environment: Any
• Frameworks: Any

Additional context
The bug was introduced in 4.7.0, as the same test passes with 4.6.x or previous versions of the client.

Information Checklist
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• Bug Description Added
• Repro Steps Added
• Setup information Added

[vcolin7]

Hi @nagyesta, thanks for reporting this and even more for creating a PR that addresses the issue, we love receiving contributions from the community. I will review it and provide any relevant feedback before EOD. I'm sure that if we can get this merged before the end of the week we can include it in next week's release :)