dashboard: Update TiDB Dashboard to v2021.06.15.1 (#3785)#3798

Merged

ti-chi-bot merged 7 commits intotikv:release-5.0from shhdgit:cherry-pick-3785-to-release-5.0

Jun 25, 2021

+25-26

Commits on Jun 17, 2021

This is an automated cherry-pick of tikv#3785

shhdgit
authored and
ti-chi-bot
committed

Commits on Jun 18, 2021

Resolve conflict
shhdgit
committed