Handle track_total_hits=False in elasticsearch instrumentation

[basepi]

What does this pull request do?

In case track_total_hits=False, we weren't properly checking to make sure the total hits were available.

Related issues

Closes #1686

[apmmachine]

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• Start Time: 2022-11-03T00:26:05.430+0000

• Duration: 20 min 59 sec

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Test	Results
Failed	0
Passed	5081
Skipped	3505
Total	8586

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🌐 Coverage report

Name	Metrics % (covered/total)	Diff
Packages	100.0% (68/68)	💚
Files	100.0% (230/230)	💚
Classes	100.0% (230/230)	💚
Lines	92.192% (18456/20019)	👍 0.008
Conditionals	75.244% (2854/3793)	👍

[beniwohli]

LGTM!