[Elastic Agent] Set metric type

[constanca-m]

What does this PR do?

Set metric type for metric fields missing it.

For the filebeat_input data stream:

• object type fields had to be converted for numeric field types. The reason for this is explained in this issue.
• Can you please check:
  1. *.histogram.count is a gauge? My reasoning is that the next value can be less than the current value, so it keeps going up and down. Because of that it cannot be a counter.
  2. *.histogram.* is a gauge for the same reasoning?

Checklist

• I have reviewed tips for building integrations and this pull request is aligned with them.
• I have verified that all data streams collect metrics or logs.
• I have added an entry to my package's changelog.yml file.
• I have verified that Kibana version constraints are current according to guidelines.

Related issues

Relates to #6938.

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• Start Time: 2023-08-01T06:51:10.668+0000

• Duration: 14 min 22 sec

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Passed	37
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Total	37

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Name	Metrics % (covered/total)	Diff
Packages	100.0% (0/0)	💚
Files	100.0% (0/0)	💚 2.828
Classes	100.0% (0/0)	💚 2.828
Methods	33.333% (25/75)	👎 -58.96
Lines	100.0% (0/0)	💚 9.02
Conditionals	100.0% (0/0)	💚