Description of problem: In the y-upgrade env, the default label is autolabel on the Grafana dashboard, it causes not all clusters to be listed by default.

Does it regression to fix the previous issue to change the default label to `name`?

Version-Release number of selected component (if applicable):

How reproducible:

Steps to Reproduce:

1. upgrade ACM from 2.6.z to 2.7.z to 2.8 RC9
2. Open the Grafana Dashboard, the default label is autolabel
3. all managed clusters are not listed by default

Actual results:

Expected results:

Additional info: