Percent in plaintext secret changed to "%25" when using Secrets Manager Get Secret task

**Describe the bug**

Percent in plaintext secret changed to "%25" when using Secrets Manager Get Secret task.

**To reproduce**
When fetching the secret using the AWS Toolkit for Microsoft Azure, the percent symbol is getting encoded and thus the authentication fails.
The value being populated into the build variable appears to encode that symbol as "%25" instead of leaving it as just a percent symbol.

Start with the Secrets Manager Get Secret task and reproduce the issue using a secret containing a percent symbol. Trace how the fetched value is populated into the Azure DevOps build variable; done means the percent remains unencoded and authentication succeeds.

Written by the indexing model from the issue text.