Creating best impression in interview is certainly a challenge for everybody, and personal grooming decisions is certainly a task fir everybody. A major question which arises in every male candidate mind is that whether he should shave or not.
It is certainly advised that male candidates should shave before a interview it makes them look more cleaner and presentable, but it certainly depends from the perspective of the interviewer some interviewer having a clean shave look is not always important, perhaps some people look more presentable in well groomed beard as compared to clean shave.
Hence, its completely up to you if you think that a beard increases your personality have a beard but it should be well groomed and maintained so that it will look presentable.
If you are still not sure it is advised that you should go for a clean shave look.