Make Overlay service tree shakable

[mertdeg2]

Bug, feature request, or proposal:

Feature request

What is the expected behavior?

Overlay service is tree shakable

What is the current behavior?

Overlay service is NOT tree shakable

What is the use-case or motivation for changing an existing behavior?

This is preventing us from making our services that depend on Overlay service tree shakable.

[crisbeto]

Duplicate of #18944.

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