Bump addon-manager to v8.7

[MrHohn]

What this PR does / why we need it:
Major changes:

• Support extra --prune-whitelist resources in kube-addon-manager.
• Update kubectl to v1.10.7.

Basically picking up #67743.

Which issue(s) this PR fixes (optional, in fixes #<issue number>(, fixes #<issue_number>, ...) format, will close the issue(s) when PR gets merged):
Fixes #NONE

Special notes for your reviewer:
/assign @Random-Liu @mikedanese

Release note:

Bump addon-manager to v8.7
- Support extra `--prune-whitelist` resources in kube-addon-manager.
- Update kubectl to v1.10.7.

[Random-Liu]

/lgtm

[Random-Liu]

ping @mikedanese for approval. :)

[mikedanese]

/approve

[k8s-ci-robot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: mikedanese, MrHohn, Random-Liu

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Needs approval from an approver in each of these files:

• cluster/OWNERS [mikedanese]
• test/kubemark/OWNERS [MrHohn,mikedanese]

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[mikedanese]

why not 1.11?

[MrHohn]

Just in case we would need to cherrypick this to 1.10.

[MrHohn]

/priority critical-urgent

[k8s-github-robot]

Automatic merge from submit-queue (batch tested with PRs 68087, 68256, 64621, 68299, 68296). If you want to cherry-pick this change to another branch, please follow the instructions here: /~https://github.com/kubernetes/community/blob/master/contributors/devel/cherry-picks.md.