Validating file type via magic of an AES encrypted .ts file
For a well-designed block cipher like AES, its output should be indistinguishable from random noise except to someone who knows the key, so this is not possible in the general case.

The larger problem here, however, seems to be that you are trying to use the magic tests to verify file integrity without having any other protections. Confidentiality (as provided by encryption) does not guarantee integrity, and vice versa. You should use an authenticated encryption mode that handles both or find another way to create a system that provides both confidentiality and integrity.