Bluetooth: Mesh: Initialize UUID in shell's mod_pub_set
Bluetooth: Mesh: Initialize UUID in shell's mod_pub_set

PR #35774 introduced a uuid field in the bt_mesh_cfg_mod_pub structure.
The shell does not initialize this pointer before passing it to the
access layer. Add a line to initialize this pointer.

Fixes #38016.

Signed-off-by: Trond Einar Snekvik <cbf21a7cf058d7ce8e74b0726695057d761f6ae9@nordicsemi.no>

galak/zephyr,zephyrproject-rtos/zephyr,zephyrproject-rtos/zephyr,finikorg/zephyr,zephyrproject-rtos/zephyr,galak/zephyr,galak/zephyr,galak/zephyr,finikorg/zephyr,zephyrproject-rtos/zephyr,zephyrproject-rtos/zephyr,finikorg/zephyr,finikorg/zephyr,finikorg/zephyr,galak/zephyr