Add previously released API to test-api-stubs-docs-non-updatable

Previously, `test-api-stubs-docs-non-updatable` did not have a
previously released API as test APIs were not tracked like other API
surfaces in `prebuilts/sdk`. However, since 36 they are tracked.

This change adds the previously released API as it is necessary for
supporting moving flagged APIs from `system` (which `test` extends)
to `public` and also to support moving flagged APIs from `test` to
another surface like `system` or `public`.

Flag: EXEMPT build fix to improve flag support
Bug: 425309457
Test: TH
Change-Id: Icfb756458425200807ab3e0254fd5ddb6bc78c88