Define GUID for boot manage policy to connecxt storage devices. (#619)

## Description

Some devices may require connecting storage media while booting to
network or require enumerating storage protocols that were not initially
enumerated during DXE. This change adds a GUID to allow implementation
of boot manager's ConnectDeviceClass to connect storage media.

- [ ] Impacts functionality?
- [ ] Impacts security?
- [ ] Breaking change?
- [ ] Includes tests?
- [ ] Includes documentation?

## How This Was Tested

N/A

## Integration Instructions

N/A

MdePkg/Include/Protocol/BootManagerPolicy.h

@@ -31,6 +31,13 @@
     0x113B2126, 0xFC8A, 0x11E3, { 0xBD, 0x6C, 0xB8, 0xE8, 0x56, 0x2C, 0xBA, 0xFA } \
   }
 
+// MU_CHANGE START: Introduce disk connect guid
+#define EFI_BOOT_MANAGER_POLICY_STORAGE_GUID \
+  { \
+    0XCD68FE79, 0XD3CB, 0X436E, {0XA8, 0X50, 0XF4, 0X43, 0XC8, 0X8C, 0XFB, 0X49 }\
+  }
+// MU_CHANGE END
+
 typedef struct _EFI_BOOT_MANAGER_POLICY_PROTOCOL EFI_BOOT_MANAGER_POLICY_PROTOCOL;
 
 #define EFI_BOOT_MANAGER_POLICY_PROTOCOL_REVISION  0x00010000
@@ -98,6 +105,14 @@ EFI_STATUS
   EFI_BOOT_SERVICES.ConnectController(). If the Boot Manager has policy
   associated with connect all UEFI drivers this policy will be used.
 
+  MU_CHANGE START: Introduce disk connect guid
+  If Class is EFI_BOOT_MANAGER_POLICY_STORAGE_GUID then the Boot Manager will
+  connect the protocols associated with the discoverable storage disks. This may include
+  EFI_BLOCK_IO_PROTOCOL, EFI_SIMPLE_FILE_SYSTEM_PROTOCOL, or other storage protocols
+  appropriate to the device. Some platforms may choose to restrict the connected
+  devices to exclude USB or other peripherals.
+  MU_CHANGE END
+
   A platform can also define platform specific Class values as a properly generated
   EFI_GUID would never conflict with this specification.
 
@@ -128,5 +143,6 @@ extern EFI_GUID  gEfiBootManagerPolicyProtocolGuid;
 extern EFI_GUID  gEfiBootManagerPolicyConsoleGuid;
 extern EFI_GUID  gEfiBootManagerPolicyNetworkGuid;
 extern EFI_GUID  gEfiBootManagerPolicyConnectAllGuid;
+extern EFI_GUID  gEfiBootManagerPolicyStorageGuid; // MU_CHANGE: Introduce disk connect guid
 
 #endif

MdePkg/MdePkg.dec

@@ -699,6 +699,7 @@
   gEfiBootManagerPolicyConsoleGuid    = { 0xCAB0E94C, 0xE15F, 0x11E3, { 0x91, 0x8D, 0xB8, 0xE8, 0x56, 0x2C, 0xBA, 0xFA }}
   gEfiBootManagerPolicyNetworkGuid    = { 0xD04159DC, 0xE15F, 0x11E3, { 0xB2, 0x61, 0xB8, 0xE8, 0x56, 0x2C, 0xBA, 0xFA }}
   gEfiBootManagerPolicyConnectAllGuid = { 0x113B2126, 0xFC8A, 0x11E3, { 0xBD, 0x6C, 0xB8, 0xE8, 0x56, 0x2C, 0xBA, 0xFA }}
+  gEfiBootManagerPolicyStorageGuid    = { 0XCD68FE79, 0XD3CB, 0X436E, {0XA8, 0X50, 0XF4, 0X43, 0XC8, 0X8C, 0XFB, 0X49 }} # MU_CHANGE: Introduce disk connect guid
 
   ## Include/Protocol/DevicePath.h
   gEfiVirtualDiskGuid            = { 0x77AB535A, 0x45FC, 0x624B, {0x55, 0x60, 0xF7, 0xB2, 0x81, 0xD1, 0xF9, 0x6E }}