[Fix] Fix testing without labels features

[bjzhb666]

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Motivation

Now, testing with labels is the default setting, which is not common.

Modification

Change the default value from True to False

BC-breaking (Optional)

NO.

Use cases (Optional)

No need.

Checklist

1. Pre-commit or other linting tools are used to fix the potential lint issues.
2. The modification is covered by complete unit tests. If not, please add more unit test to ensure the correctness.
3. If the modification has potential influence on downstream projects, this PR should be tested with downstream projects, like MMDet or MMDet3D.
4. The documentation has been modified accordingly, like docstring or example tutorials.

[CLAassistant]

All committers have signed the CLA.

[MGAMZ]

Maybe it's a better solution to modify this param in config, rather than directly modify default values globally, considering most datasets have named labels.