Bug - Adjusting nvsdkmanager_flash.sh to avoid 14GB nvme SSD partition

[rhysdg]

• Adding a quick change to flash_jetson_external_storage.sh that modifies `nvsdkmanager_flash.sh at the current L4T version
• Without this change flashing resulted in a 14GB partition that was difficult to change with gparted due to the fact that it was the the system root/ used for boot etc
• the solution that lead to this quick change was taken from this tech support [solution] (https://forums.developer.nvidia.com/t/jetpack-5-1-2-l4t-35-4-1-is-now-live/262035/5)

Environment

• Ubuntu 22.04 (Host)
• Jetson NX Xavier 8GB Development Kit (Target)
• Jetson AGX Xavier 32GB Development Kit (Target)

Test Results - Tested succesfully for changes with Jetpack 5.4.1 and a 500GB WD Blue NVMe SSD