No byte[] decrypt / encrypt in api-management-policy-snippets/examples /Encrypt data using expressions.policy.xml

Encrypt data using expressions.policy.xml and Decrypt AES Data using policy expressions.xml appear not to work.
```
byte[] inBytes = Convert.FromBase64String(context.Request.Body.As().SelectToken("encrpText").ToString());
byte[] decryptedBytes = **inBytes.Decrypt**("Aes", key, IV);**
```
```
byte[] gooberBytes = Encoding.UTF8.GetBytes(goober);
byte[] encryptedBytes = gooberBytes**.Encrypt("Aes", key, IV);**
```
Byte[] doesn't have an encrypt or decrypt method. It also appears that symmetrical encryption isn't possible in API management.

Start by opening examples/Encrypt data using expressions.policy.xml and Decrypt AES Data using policy expressions.xml and checking the byte[] Encrypt and Decrypt calls shown in the issue. Verify whether those operations are supported in API Management policy expressions; done means the examples work as documented or clearly state the limitation and supported approach.

Written by the indexing model from the issue text.