If restart pod sanbox, rewrite etc resolv.conf again.

[wangforthinker]

Ⅰ. Describe what this PR did

fix if restart pod sanbox container, sanbox /etc/resolv.conf will be restore to host /etc/resolv.conf.

Ⅱ. Does this pull request fix one issue?

None.

Ⅲ. Why don't you add test cases (unit test/integration test)? (你真的觉得不需要加测试吗？)

none.

Ⅳ. Describe how to verify it

Ⅴ. Special notes for reviews

[codecov]

Codecov Report

Merging #2843 into master will decrease coverage by 1.79%.
The diff coverage is 0%.

@@           Coverage Diff            @@
##           master   #2843     +/-   ##
========================================
- Coverage   69.09%   67.3%   -1.8%     
========================================
  Files         285     285             
  Lines       17844   17848      +4     
========================================
- Hits        12330   12013    -317     
- Misses       4114    4481    +367     
+ Partials     1400    1354     -46

Flag	Coverage Δ
#criv1alpha2_test	39.05% <0%> (+0.04%)	⬆️
#integration_test_0	36.55% <0%> (-0.02%)	⬇️
#integration_test_1	?
#integration_test_2	36.49% <0%> (+0.02%)	⬆️
#integration_test_3	35.46% <0%> (ø)	⬆️
#node_e2e_test	34.77% <0%> (-0.01%)	⬇️
#unittest	28.52% <0%> (-0.01%)	⬇️

Impacted Files	Coverage Δ
cri/v1alpha2/cri.go	69.22% <0%> (+0.15%)	⬆️
ctrd/image_commit.go	0% <0%> (-69.29%)	⬇️
daemon/mgr/container_commit.go	0% <0%> (-56.1%)	⬇️
daemon/mgr/container_checkpoint.go	54.21% <0%> (-14.46%)	⬇️
pkg/reference/def.go	77.77% <0%> (-11.12%)	⬇️
daemon/mgr/network_utils.go	30.43% <0%> (-10.87%)	⬇️
daemon/mgr/events.go	87.5% <0%> (-9.73%)	⬇️
apis/server/network_bridge.go	57.25% <0%> (-8.88%)	⬇️
daemon/mgr/container_exec.go	71.54% <0%> (-8.14%)	⬇️
apis/server/container_bridge.go	82.5% <0%> (-7.5%)	⬇️
... and 19 more

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