Deploying the very same POD twice throws error

**What steps did you take:**
edeoliveira:~/Documents/projects/carvel-research
$ k create ns app4 && kapp deploy -a app3 -n app --into-ns app4 -f busybox-pod.yaml
namespace/app4 created
Target cluster 'https://kubernetes.docker.internal:6443' (nodes: docker-desktop)

Changes

Namespace Name Kind Conds. Age Op Op st. Wait to Rs Ri
app3 bb Pod 4/4 t 2d delete - delete ok -
app4 bb Pod - - create - reconcile - -

Op: 1 create, 1 delete, 0 update, 0 noop
Wait to: 1 reconcile, 1 delete, 0 noop

Continue? [yN]: y

10:03:34AM: ---- applying 2 changes [0/2 done] ----
10:03:34AM: delete pod/bb (v1) namespace: app3
10:03:35AM: create pod/bb (v1) namespace: app4
10:03:35AM: ---- waiting on 2 changes [0/2 done] ----
10:03:35AM: ongoing: delete pod/bb (v1) namespace: app3
10:03:35AM: ongoing: reconcile pod/bb (v1) namespace: app4
10:03:35AM: ^ Pending: ContainerCreating
10:03:38AM: ok: reconcile pod/bb (v1) namespace: app4
10:03:38AM: ---- waiting on 1 changes [1/2 done] ----
10:04:11AM: ok: delete pod/bb (v1) namespace: app3
10:04:11AM: ---- applying complete [2/2 done] ----
10:04:11AM: ---- waiting complete [2/2 done] ----

Succeeded

edeoliveira:~/Documents/projects/carvel-research
$ k create ns app4 && kapp deploy -a app3 -n app --into-ns app4 -f busybox-pod.yaml
Error from server (AlreadyExists): namespaces "app4" already exists

edeoliveira:~/Documents/projects/carvel-research
$ kapp deploy -a app3 -n app --into-ns app4 -f busybox-pod.yaml
Target cluster 'https://kubernetes.docker.internal:6443' (nodes: docker-desktop)

Changes

Namespace Name Kind Conds. Age Op Op st. Wait to Rs Ri
app4 bb Pod - 51s update - reconcile ok -

Op: 0 create, 0 delete, 1 update, 0 noop
Wait to: 1 reconcile, 0 delete, 0 noop

Continue? [yN]: y

10:04:27AM: ---- applying 1 changes [0/1 done] ----
10:04:27AM: update pod/bb (v1) namespace: app4

kapp: Error: Applying update pod/bb (v1) namespace: app4:
Updating resource pod/bb (v1) namespace: app4:
Pod "bb" is invalid: spec:
Forbidden: pod updates may not change fields other than `spec.containers[*].image`, `spec.initContainers[*].image`, `spec.activeDeadlineSeconds` or `spec.tolerations` (only additions to existing tolerations)
  core.PodSpec{
-  Volumes: nil,
+  Volumes: []core.Volume{
+  {
+  Name: "default-token-gkbbh",
+  VolumeSource: core.VolumeSource{
+  Secret: &core.SecretVolumeSource{SecretName: "default-token-gkbbh", DefaultMode: &420},
+  },
+  },
+  },
   InitContainers: nil,
   Containers: []core.Container{
   {
   ... // 7 identical fields
   Env: nil,
   Resources: core.ResourceRequirements{},
-  VolumeMounts: nil,
+  VolumeMounts: []core.VolumeMount{
+  {
+  Name: "default-token-gkbbh",
+  ReadOnly: true,
+  MountPath: "/var/run/secrets/kubernetes.io/serviceaccount",
+  },
+  },
   VolumeDevices: nil,
   LivenessProbe: nil,
   ... // 10 identical fields
   },
   },
   EphemeralContainers: nil,
   RestartPolicy: "Always",
   ... // 2 identical fields
   DNSPolicy: "ClusterFirst",
   NodeSelector: nil,
-  ServiceAccountName: "",
+  ServiceAccountName: "default",
   AutomountServiceAccountToken: nil,
   NodeName: "docker-desktop",
   ... // 18 identical fields
  }
(reason: Invalid)

**What happened:**
The same POD yaml deployed twice resulted on invalid field changes error. Nothing was changed!

**What did you expect:**
A message saying `No changes found in the new configuration`

**Anything else you would like to add:**
[Additional information that will assist in solving the issue.]

**Environment:**

- kapp version (use `kapp --version`): kapp version 0.36.0

- OS (e.g. from `/etc/os-release`): MacOs 11.2.3
- Kubernetes version (use `kubectl version`)
Client Version: version.Info{Major:"1", Minor:"20", GitVersion:"v1.20.4", GitCommit:"e87da0bd6e03ec3fea7933c4b5263d151aafd07c", GitTreeState:"clean", BuildDate:"2021-02-21T20:23:45Z", GoVersion:"go1.15.8", Compiler:"gc", Platform:"darwin/amd64"}
Server Version: version.Info{Major:"1", Minor:"19", GitVersion:"v1.19.3", GitCommit:"1e11e4a2108024935ecfcb2912226cedeafd99df", GitTreeState:"clean", BuildDate:"2020-10-14T12:41:49Z", GoVersion:"go1.15.2", Compiler:"gc", Platform:"linux/amd64"}
Docker version 20.10.2, build 2291f61 (embedded k8s cluster)