bug: Some typos in grafana dashboard

[haorenfsa]

Description:

What issue is being seen? Describe what should be happening instead of
the bug, for example: Envoy should not crash, the expected value isn't
returned, etc.

Repro steps:

Include sample requests, environment, etc. All data and inputs
required to reproduce the bug.

Upstream Bytes Tx/Second uses RX metric by mistake.

Allocated memroy uses SUM by mistake (should be lower sum), causes dashboard crash when being edited.

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Environment:

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Logs:

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