feature: add cri metrics

[starnop]

Signed-off-by: Starnop [email protected]

Ⅰ. Describe what this PR did

add metrics about grpc server of CRI Manager.

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？)

Ⅳ. Describe how to verify it

Ⅴ. Special notes for reviews

[codecov]

Codecov Report

Merging #2304 into master will increase coverage by 0.26%.
The diff coverage is 87.93%.

@@            Coverage Diff             @@
##           master    #2304      +/-   ##
==========================================
+ Coverage   66.97%   67.23%   +0.26%     
==========================================
  Files         211      213       +2     
  Lines       17306    17465     +159     
==========================================
+ Hits        11591    11743     +152     
- Misses       4312     4327      +15     
+ Partials     1403     1395       -8

Flag	Coverage Δ
#criv1alpha1test	32.15% <28.64%> (+0.07%)	⬆️
#criv1alpha2test	36.13% <81.4%> (+0.53%)	⬆️
#integrationtest	39.91% <30.15%> (-0.27%)	⬇️
#nodee2etest	33.67% <84.42%> (+0.55%)	⬆️
#unittest	23.21% <0.74%> (-0.2%)	⬇️

Impacted Files	Coverage Δ
apis/metrics/metrics.go	100% <ø> (ø)	⬆️
apis/server/image_bridge.go	72.72% <100%> (ø)	⬆️
cri/v1alpha2/service/cri.go	89.47% <100%> (+3.75%)	⬆️
pkg/utils/metrics/metrics.go	100% <100%> (ø)
cri/metrics/metrics.go	100% <100%> (ø)
cri/v1alpha2/cri.go	68.85% <81.95%> (+2.52%)	⬆️
daemon/mgr/snapshot.go	89.85% <0%> (-4.35%)	⬇️
cri/v1alpha2/cri_wrapper.go	61.2% <0%> (-1.2%)	⬇️
... and 8 more

[fuweid]

LGTM