If your bankruptcy has been discharged by the time you receive the inheritance, you do not need to worry as it will be yours.

If you were to receive the inheritance whilst still bankrupt, then it would be an issue.

This is from the government's insolvency web site regarding this:

Whether or not a bankrupt or former bankrupt can benefit under the terms
of a will would depend upon the date of inheritance. If the money is
inherited whilst the bankrupt is undischarged from the proceedings, i.e.
the date of death is before the bankrupt is discharged, then the
bankrupt has a duty to notify his trustee in bankruptcy of the
inheritance and the trustee can claim the inheritance as after-acquired
property for the benefit of the bankruptcy estate.

If the money is inherited after discharge, i.e. date of death is after
discharge, the inheritance is not a bankruptcy asset and the former
bankrupt has no obligation to inform the official receiver or trustee in
bankruptcy.

If someone who is made bankrupt knows that they are mentioned in a
person's will they would have no obligation to mention this to the
trustee, as it is not an asset until the benefactor dies and, until the
date of death, that person has the freedom to change their will as they
choose.

So just because you are mentioned in a Will and go bankrupt, you do not need to disclose this.

However, if your grand-dad has passed, and the estate settled and you are to receive the inheritance in two years, but have been notified of the inheritance whilst bankrupt, you would need to disclose this and the Receiver may place an interest in this.