Tests: bluetooth: tester: find connection for get_attr_val_rp
Tests: bluetooth: tester: find connection for get_attr_val_rp

To check security of connection  in read_value() we need to actually
pass connection not NULL.

This is affecting GATT/SR/GAR/BI-11-C

Signed-off-by: Krzysztof Kopyściński <48568cfaa134e87f8b8a21a5eb21757e127be81c@codecoup.pl>

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