Fix resource import test's new and old ID assertion

[ulucinar]

Description of your changes

In https://github.com/upbound/provider-aws/actions/runs/6460833777/job/17539319778, we have encountered the following error in the resource import tests:

...
logger.go:42: 19:43:15 | case/2-import | running command: [sh -c new_id=$(${KUBECTL} get streamconsumer.kinesis.aws.upbound.io/example -o=jsonpath='{.status.atProvider.id}') && old_id=$(${KUBECTL} get streamconsumer.kinesis.aws.upbound.io/example -o=jsonpath='{.metadata.annotations.uptest-old-id}') && [ "$new_id" == "$old_id" ]]
logger.go:42: 19:43:15 | case/2-import | sh: 1: [: arn:aws:kinesis:us-west-1:153891904029:stream/example/consumer/example-consumer:1696879709: unexpected operator
logger.go:42: 19:43:15 | case/2-import | command failure, skipping 2 additional commands
...

We need to use the = operator instead of the == operator with sh.

I have:

• Run make reviewable test to ensure this PR is ready for review.

How has this code been tested

Tested manually with sh.

[sergenyalcin]

Thanks @ulucinar LGTM!

[github-actions]

Successfully created backport PR #152 for release-0.6.