[XLA] Remove ServiceInterface
[XLA] Remove ServiceInterface

The abstraction does not add much value over just using Service class.

FUTURE_COPYBARA_INTEGRATE_REVIEW=https://github.com/openxla/xla/pull/13477 from shraiysh:fix-while-loop-derived-instruction 9563c00004bc2a988d01964f213e5dc4dc535489
