Update base for Update on "[ET-VK] Renaming slice_channel and slice_batch_height_width files to reflect change in its utility."

This diff renames files `slice_batch_height_width.y*` to `slice_unpacked_dim.*` and `slice_channel.*` to `slice_packed_dim.*` to reflect the change in their utility after enabling all dim packing for slice op.

Differential Revision: [D70919994](https://our.internmc.facebook.com/intern/diff/D70919994/)

[ghstack-poisoned]

Author: trivedivivek