Add test case to validate no err is returned when cmd is kapp

Signed-off-by: Devanshu <devanshu.d@broadcom.com>

cli/pkg/kctrl/cmd/app/release/release_cmd_runner_test.go

@@ -0,0 +1,16 @@
+package release
+
+import (
+	"os"
+	"os/exec"
+	"testing"
+
+	"github.com/stretchr/testify/require"
+)
+
+func TestReleaseCmdRunnerForKappCmd(t *testing.T) {
+	ReleaseCmdRunner := NewReleaseCmdRunner(os.Stdout, false, "", false, nil)
+	cmd := exec.Command("kapp", "deploy", "-f", "-", "-a", "pkg-test", "-y")
+	err := ReleaseCmdRunner.RunWithCancel(cmd, nil)
+	require.NoError(t, err)
+}