Update on "[ET-VK] Tuning conv 2d pw op tile size to improve perf."

This diff tunes the tile size for the conv 2d pw op to improve performance. The changes include updating the `TILE_SIZE_X` and `TILE_SIZE_Y` values in the `conv2d_pw.yaml` files and modifying the `Convolution.cpp` files to adjust the image extents calculation. The `TILE_SIZE_X` value is changed from 2 to 1, and the `TILE_SIZE_Y` value is changed from 2 to 4.

Differential Revision: [D75317820](https://our.internmc.facebook.com/intern/diff/D75317820/)

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Author: trivedivivek