Add ca-certificates directory for distros that do not include it

[tstromberg]

Fixes #6542

[k8s-ci-robot]

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[codecov-io]

Codecov Report

Merging #6545 into master will decrease coverage by 0.02%.
The diff coverage is 84%.

@@            Coverage Diff             @@
##           master    #6545      +/-   ##
==========================================
- Coverage   37.91%   37.88%   -0.03%     
==========================================
  Files         137      137              
  Lines        8683     8676       -7     
==========================================
- Hits         3292     3287       -5     
+ Misses       4978     4976       -2     
  Partials      413      413

Impacted Files	Coverage Δ
pkg/minikube/bootstrapper/bsutil/versions.go	81.81% <ø> (ø)	⬆️
pkg/minikube/cluster/start.go	52.33% <ø> (ø)	⬆️
pkg/minikube/bootstrapper/bsutil/kubeadm.go	82.08% <100%> (ø)	⬆️
cmd/minikube/cmd/start.go	22.17% <16.66%> (+0.07%)	⬆️
pkg/minikube/bootstrapper/certs.go	75.24% <87.5%> (ø)	⬆️
cmd/minikube/cmd/env.go	57.37% <94.28%> (-0.44%)	⬇️

[medyagh]

/ok-to-test

[minikube-pr-bot]

All Times Minikube (PR 6545): [ 95.955883 92.372326 91.608516]
All Times minikube: [ 91.065509 93.047647 94.101828]

Average Minikube (PR 6545): 93.312242
Average minikube: 92.738328

Averages Time Per Log

+----------------------+-----------+--------------------+
|         LOG          | MINIKUBE  | MINIKUBE (PR 6545) |
+----------------------+-----------+--------------------+
| minikube v           |  0.206669 |           0.204820 |
| Creating kvm2        | 19.782795 |          20.205173 |
| Preparing Kubernetes | 50.196398 |          49.882246 |
| Pulling images       |           |                    |
| Launching Kubernetes | 20.706054 |          21.406061 |
| Waiting for cluster  |  0.236699 |           0.064100 |
+----------------------+-----------+--------------------+