Is there any way to hide message length from adversary in symmetric key cryptography?
Suppose we want to hide message length from active and efficient adversaries.
Yes, you can pad the message with zero's or random values. As long as you can retrieve the location of the message inside the padded plaintext then you can hide the exact message length.
Note that statistical methods can still be applied; you will have to always create a message size of $N$ if you want to full hide the length of messages of $0$ to $N$ in length - excluding normal padding that may be required for block modes of encryption. Obviously, you still leak the information that the message is lower than $N$. But that cannot be avoided; an encrypted message of size $N$ cannot be created for all messages larger than $N$.
Just adding a (random) padding of random length may not be good enough as you will still leak some data about the message size if you average things out. This paper by Cihangir Tezcan and Serge Vaudenay makes it clear that providing random padding cannot practically hide enough information when a minimum amount of security is required. It still depends on the use case if random (sized) padding is sufficient for a use case, but it should be avoided.