Skip kubeadm if cluster is running & properly configured

[tstromberg]

In combination with #7115 - this speeds up "minikube start" on a running cluster so that it only takes ~3 seconds.

This should also improve reliability when "minikube start" is run on a running cluster, as it has less work to do.

[k8s-ci-robot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: tstromberg

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[codecov-io]

Codecov Report

Merging #7124 into master will decrease coverage by 0.00%.
The diff coverage is 0.00%.

@@            Coverage Diff             @@
##           master    #7124      +/-   ##
==========================================
- Coverage   36.96%   36.95%   -0.01%     
==========================================
  Files         145      145              
  Lines        9165     9167       +2     
==========================================
  Hits         3388     3388              
- Misses       5359     5361       +2     
  Partials      418      418              

Impacted Files	Coverage Δ
pkg/minikube/bootstrapper/bsutil/binaries.go	5.12% <0.00%> (-0.28%)	⬇️
pkg/minikube/bootstrapper/bsutil/files.go	0.00% <0.00%> (ø)

[tstromberg]

/ok-to-test

[minikube-pr-bot]

All Times Minikube (PR 7124): [ 66.037811 66.203720 64.962396]
All Times minikube: [ 68.052642 63.957943 63.246795]

Average minikube: 65.085793
Average Minikube (PR 7124): 65.734642

Averages Time Per Log

+----------------------+-----------+--------------------+
|         LOG          | MINIKUBE  | MINIKUBE (PR 7124) |
+----------------------+-----------+--------------------+
| minikube v           |  0.218078 |           0.219074 |
| Creating kvm2        | 41.835136 |          41.357480 |
| Preparing Kubernetes |  1.012549 |           0.767338 |
| Pulling images       |           |                    |
| Launching Kubernetes | 20.080977 |          21.150909 |
| Waiting for cluster  |  0.230517 |           0.566989 |
+----------------------+-----------+--------------------+

[minikube-pr-bot]

All Times Minikube (PR 7124): [ 68.036779 67.438663 64.682441]
All Times minikube: [ 64.861405 66.250171 64.055292]

Average minikube: 65.055623
Average Minikube (PR 7124): 66.719294

Averages Time Per Log

+----------------------+-----------+--------------------+
|         LOG          | MINIKUBE  | MINIKUBE (PR 7124) |
+----------------------+-----------+--------------------+
| minikube v           |  0.222339 |           0.209298 |
| Creating kvm2        | 41.095940 |          43.238951 |
| Preparing Kubernetes | 21.652971 |          21.236913 |
| Pulling images       |           |                    |
| Launching Kubernetes |           |                    |
| Waiting for cluster  |  0.410265 |                    |
+----------------------+-----------+--------------------+