Input checks for policy rules (#2771)
Input checks for policy rules (#2771)

* Input checks for policy rules

* Address review feedback

deverton/hashicorp-vault,rnaveiras/vault,rnaveiras/vault,hashicorp/vault,Aloomaio/vault,hartsock/vault,kingland/vault,rnaveiras/vault,Aloomaio/vault,naunga/vault,Aloomaio/vault,joelthompson/vault,hartsock/vault,joelthompson/vault,hashicorp/vault,Caiyeon/vault,hashicorp/vault,kingland/vault,quixoten/vault,quixoten/vault,rnaveiras/vault,lemondrank/vault,hartsock/vault,Aloomaio/vault,quixoten/vault,hashicorp/vault,kingland/vault,kingland/vault,mgk/vault,mgk/vault,hashicorp/vault,lirao/vault,quixoten/vault,tallpauley/vault,mgk/vault,MonsantoCo/vault,joelthompson/vault,lirao/vault,lemondrank/vault,hartsock/vault,wjam/vault,mgk/vault,naunga/vault,Caiyeon/vault,hashicorp/vault,joelthompson/vault,MonsantoCo/vault,hartsock/vault,rnaveiras/vault,wjam/vault,deverton/hashicorp-vault,tallpauley/vault,kingland/vault