Support monitor helm chart

[bzheng888]

What changes are proposed in this pull request?

Add a monitor helm chart to monitor alluxio cluster in kubernetes, view the README.md for detail information.

Why are the changes needed?

Easy to deploy a monitor system (grafana + prometheus) in kubernetes.

Does this PR introduce any user facing changes?

We can view cluster information by using grafana page just like this:

[bzheng888]

@ssz1997 @ZhuTopher The error is not caused by this pr，PTAL, thx!

[ssz1997]

@bzheng888 It's fixed now. Please pull the latest master. Let me know when it's ready for review

[bzheng888]

@ssz1997 Seems no errors, PTAL!

[bzheng888]

@ssz1997 PTAL!

[ZhuTopher]

Failing unit test is unrelated to PR changes:

Error: 4.672 [ERROR] Errors: 
Error: 4.672 [ERROR] alluxio.server.ft.journal.raft.EmbeddedJournalIntegrationTestTransferLeadership.resetPriorities
Error: 4.673 [ERROR]   Run 1: EmbeddedJournalIntegrationTestTransferLeadership.resetPriorities:207->transferAndWait:250->EmbeddedJournalIntegrationTestBase.waitForQuorumPropertySize:58 » Timeout
Error: 4.674 [ERROR]   Run 2: EmbeddedJournalIntegrationTestTransferLeadership.resetPriorities:207->transferAndWait:250->EmbeddedJournalIntegrationTestBase.waitForQuorumPropertySize:58 » Timeout

[ssz1997]

@ZhuTopher @jiacheliu3 Take a look if you have time?

[LuQQiu]

Based on the community sync discussion, @bzheng888 please put the big file to dashboard? or other place that available to end-users?

[bzheng888]

@jiacheliu3 @ssz1997 @LuQQiu Where should I upload the dashboard json file after I remove it?

[LuQQiu]

@beinan this is the PR for monitoring the Alluxio system in Kubernetes

[LuQQiu]

@bzheng888 https://grafana.com/grafana/dashboards/ as @maobaolong mentioned, this website may be a good idea

[bzheng888]

@ZhuTopher @ssz1997 @jiacheliu3 @maobaolong @LuQQiu Update this pr, PTAL, the dashboard can be download from https://grafana.com/grafana/dashboards/17785-alluxio-prometheus-grafana-monitor-v1/

[LuQQiu]

@LuQQiu assigned myself for a final pass and merge the PR

[LuQQiu]

@jiacheliu3 Does this PR good to be merged? saw you haven't approved the PR

[bzheng888]

@jiacheliu3 PTAL

[jiacheliu3]

alluxio-bot, merge this please