apps/builtin: Use shell default values of priority and stacksize
apps/builtin: Use shell default values of priority and stacksize

When builtin feature is enabled and priority and stacksize is not
configured in each application, let's use default values of
priority and stacksize which is defined in shell Kconfig instead
of hard-coded in apps/Make.defs.

pillip8282/TizenRT,jeongchanKim/TizenRT,lokeshbv/TizenRT,jsdosa/TizenRT,chanijjani/TizenRT,lokeshbv/TizenRT,HONGCHAEHEE/TizenRT,junmin-kim/TizenRT,JeonginKim/TizenRT,chanijjani/TizenRT,chanijjani/TizenRT,lokeshbv/TizenRT,Samsung/TizenRT,lokeshbv/TizenRT,sunghan-chang/TizenRT,an4967/TizenRT,an4967/TizenRT,jeongchanKim/TizenRT,JeonginKim/TizenRT,chanijjani/TizenRT,pillip8282/TizenRT,an4967/TizenRT,jeongchanKim/TizenRT,jeongarmy/TizenRT,an4967/TizenRT,Samsung/TizenRT,sunghan-chang/TizenRT,HONGCHAEHEE/TizenRT,jeongarmy/TizenRT,JeonginKim/TizenRT,Samsung/TizenRT,davidfather/TizenRT,jeongarmy/TizenRT,junmin-kim/TizenRT,davidfather/TizenRT,HONGCHAEHEE/TizenRT,Samsung/TizenRT,chanijjani/TizenRT,jsdosa/TizenRT,Samsung/TizenRT,sunghan-chang/TizenRT,Samsung/TizenRT,chanijjani/TizenRT,jeongarmy/TizenRT,an4967/TizenRT,jeongchanKim/TizenRT,pillip8282/TizenRT,davidfather/TizenRT,pillip8282/TizenRT,jsdosa/TizenRT,an4967/TizenRT,jsdosa/TizenRT,HONGCHAEHEE/TizenRT,jeongchanKim/TizenRT,davidfather/TizenRT,davidfather/TizenRT,sunghan-chang/TizenRT,jeongarmy/TizenRT,sunghan-chang/TizenRT,jsdosa/TizenRT,davidfather/TizenRT,HONGCHAEHEE/TizenRT,jeongarmy/TizenRT,chanijjani/TizenRT,sunghan-chang/TizenRT,pillip8282/TizenRT,lokeshbv/TizenRT,junmin-kim/TizenRT,junmin-kim/TizenRT,jeongarmy/TizenRT,HONGCHAEHEE/TizenRT,jsdosa/TizenRT,jeongchanKim/TizenRT,pillip8282/TizenRT,JeonginKim/TizenRT,pillip8282/TizenRT,junmin-kim/TizenRT,Samsung/TizenRT,JeonginKim/TizenRT,jeongchanKim/TizenRT,sunghan-chang/TizenRT,lokeshbv/TizenRT,JeonginKim/TizenRT,junmin-kim/TizenRT,jsdosa/TizenRT,an4967/TizenRT,junmin-kim/TizenRT,davidfather/TizenRT