Export test config info to module-info while the module is uninstallable

All Robolectric tests are set as uninstallable modules, which skips the
logic exporting `test_config` and `auto_test_config` to module-info.
But downstream infra needs this information to determine if a module is
a test module. So that this change moves the logic that sets
`test_config` and `auto_test_config` for Robolectric tests out of the
snippet specifically for installable module.

Test: m out/target/product/coral/module-info.json
Bug: 268670243
Change-Id: Icf4caf3d6833f3a39927fb69c6fb76762b8f6f14