Do not checkpoint sandbox pid.

Signed-off-by: Lantao Liu <lantaol@google.com>

pkg/store/sandbox/metadata.go

@@ -46,8 +46,6 @@ type Metadata struct {
 	Name string
 	// Config is the CRI sandbox config.
 	Config *runtime.PodSandboxConfig
-	// Pid is the process id of the sandbox.
-	Pid uint32
 	// NetNSPath is the network namespace used by the sandbox.
 	NetNSPath string
 }

pkg/store/sandbox/sandbox_test.go

@@ -39,7 +39,6 @@ func TestSandboxStore(t *testing.T) {
 					Attempt:   1,
 				},
 			},
-			Pid:       1001,
 			NetNSPath: "TestNetNS-1",
 		},
 		"2": {
@@ -53,7 +52,6 @@ func TestSandboxStore(t *testing.T) {
 					Attempt:   2,
 				},
 			},
-			Pid:       1002,
 			NetNSPath: "TestNetNS-2",
 		},
 		"3": {
@@ -67,7 +65,6 @@ func TestSandboxStore(t *testing.T) {
 					Attempt:   3,
 				},
 			},
-			Pid:       1003,
 			NetNSPath: "TestNetNS-3",
 		},
 	}