align_to_input_ext_scale=True still triggers Umeyama alignment, causing 2-view input failures

[lileai]

When True the predicted extrinsics are replaced with the input ones and the depth maps are rescaled to match their metric scale. When False the function returns the internally aligned poses computed via Umeyama alignment.

Expected Behavior:
When align_to_input_ext_scale=True and valid extrinsics/intrinsics are provided, the _align_to_input_extrinsics_intrinsics() call should be completely skipped, and the input parameters should be used directly.

Actual Behavior:
Regardless of the align_to_input_ext_scale value, as long as extrinsics/intrinsics are passed, _align_to_input_extrinsics_intrinsics() is always invoked, which internally calls align_poses_umeyama(), causing inevitable failures for 2-view inputs.