tests: kernel: Validate set thread name to current thread
tests: kernel: Validate set thread name to current thread

Enhance test to validate a scenario where k_thread_name_set()
    with NULL as thread ID should set thread name to current
    thread.

Signed-off-by: Spoorthi K <c4ff46ff4cba9c2c6c6c9d55497ae534451b4309@intel.com>

explora26/zephyr,GiulianoFranchetto/zephyr,finikorg/zephyr,galak/zephyr,Vudentz/zephyr,nashif/zephyr,explora26/zephyr,ldts/zephyr,ldts/zephyr,nashif/zephyr,nashif/zephyr,finikorg/zephyr,ldts/zephyr,ldts/zephyr,finikorg/zephyr,zephyrproject-rtos/zephyr,galak/zephyr,zephyrproject-rtos/zephyr,Vudentz/zephyr,Vudentz/zephyr,finikorg/zephyr,punitvara/zephyr,nashif/zephyr,galak/zephyr,Vudentz/zephyr,GiulianoFranchetto/zephyr,galak/zephyr,explora26/zephyr,GiulianoFranchetto/zephyr,zephyrproject-rtos/zephyr,galak/zephyr,Vudentz/zephyr,zephyrproject-rtos/zephyr,punitvara/zephyr,punitvara/zephyr,explora26/zephyr,GiulianoFranchetto/zephyr,GiulianoFranchetto/zephyr,explora26/zephyr,finikorg/zephyr,zephyrproject-rtos/zephyr,punitvara/zephyr,ldts/zephyr,punitvara/zephyr,Vudentz/zephyr,nashif/zephyr