tests: lib: ringbuffer: ring_buf_peek() and ring_buf_size_get()
tests: lib: ringbuffer: ring_buf_peek() and ring_buf_size_get()

Added tests for ring_buf_size_get() and ring_buf_peek().

Fixes #37147

Signed-off-by: Christopher Friedt <76f728c1c3997bf5bfe7e9261eff720c92409a2f@gmail.com>

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