So we have to be careful in clarifying what kind of encryption you're asking for. In Azure (unlike in AWS) "Azure Disk Encryption" is OS aware and leverages bitlocker/DM-Crypt. These get generated after the system is booted and thus have limitations on the source image being encrypted:
Most of it is around Linux, but still, should be aware of that limitation. Generally I find it's easiest to simply enable the encryption during deployment rather than during packaging.