Resolve restore bootstrap

[briandowns]

Proposed Changes

Types of Changes

Verification

Scenario 1

1. Start cluster
2. Take a snapshot
3. Restore the snapshot
4. Restart cluster

Scenario 2

1. Start cluster
2. Take a snaphsot
3. Stop the cluster
4. Restore to a new node

Scenario 3

1. Start a cluster
2. Take a snapshot
3. Stop the cluster
4. Remove data directory
5. Restore the snapshot
6. Start the server
7. Add node(s)

Linked Issues

#4703

User-Facing Change

Resolve issue preventing successful restore of etcd snapshot due to change in bootstrapping logic.

Further Comments

[codecov-commenter]

Codecov Report

Merging #4704 (f8372a6) into master (e8a30a8) will decrease coverage by 0.02%.
The diff coverage is 0.00%.

@@            Coverage Diff             @@
##           master    #4704      +/-   ##
==========================================
- Coverage   10.58%   10.56%   -0.03%     
==========================================
  Files         142      142              
  Lines       10193    10216      +23     
==========================================
  Hits         1079     1079              
- Misses       8886     8909      +23     
  Partials      228      228              

Flag	Coverage Δ
unittests	10.56% <0.00%> (-0.03%)	⬇️

Flags with carried forward coverage won't be shown. Click here to find out more.

Impacted Files	Coverage Δ
pkg/bootstrap/bootstrap.go	19.04% <0.00%> (-0.96%)	⬇️
pkg/cluster/bootstrap.go	0.00% <0.00%> (ø)
pkg/etcd/etcd.go	14.54% <0.00%> (-0.02%)	⬇️
pkg/cli/cert/cert.go	0.00% <0.00%> (ø)

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update e8a30a8...f8372a6. Read the comment docs.

[brandond]

a couple nits on logging what it's doing, but looks good otherwise