MdeModulePkg: Connect VariablePolicy business logic to VariableServices

https://bugzilla.tianocore.org/show_bug.cgi?id=2522

VariablePolicy is an updated interface to
replace VarLock and VarCheckProtocol.

Add connective code to publish the VariablePolicy protocol
and wire it to either the SMM communication interface
or directly into the VariablePolicyLib business logic.

Cc: Jian J Wang <jian.j.wang@intel.com>
Cc: Hao A Wu <hao.a.wu@intel.com>
Cc: Liming Gao <liming.gao@intel.com>
Cc: Bret Barkelew <brbarkel@microsoft.com>
Signed-off-by: Bret Barkelew <brbarkel@microsoft.com>
Reviewed-by: Dandan Bi <dandan.bi@intel.com>
Acked-by: Jian J Wang <jian.j.wang@intel.com>
Reviewed-by: Liming Gao <gaoliming@byosoft.com.cn>

MdeModulePkg/Universal/Variable/RuntimeDxe/VariableSmmRuntimeDxe.c

@@ -65,6 +65,17 @@ EFI_LOCK                         mVariableServicesLock;
 EDKII_VARIABLE_LOCK_PROTOCOL     mVariableLock;
 EDKII_VAR_CHECK_PROTOCOL         mVarCheck;
 
+/**
+  The logic to initialize the VariablePolicy engine is in its own file.
+
+**/
+EFI_STATUS
+EFIAPI
+VariablePolicySmmDxeMain (
+  IN    EFI_HANDLE                  ImageHandle,
+  IN    EFI_SYSTEM_TABLE            *SystemTable
+  );
+
 /**
   Some Secure Boot Policy Variable may update following other variable changes(SecureBoot follows PK change, etc).
   Record their initial State when variable write service is ready.
@@ -1796,6 +1807,9 @@ VariableSmmRuntimeInitialize (
          &mVirtualAddressChangeEvent
          );
 
+  // Initialize the VariablePolicy protocol and engine.
+  VariablePolicySmmDxeMain (ImageHandle, SystemTable);
+
   return EFI_SUCCESS;
 }