Seems you did it already mostly right. The desired heap_4.c is included in your build:
In file included from C:\Users\Claudio Rosa\.platformio\packages\framework-arduinoadafruitnrf52\cores\nRF5\freertos\Source\include/FreeRTOS.h:56:0,
from C:\Users\Claudio Rosa\.platformio\packages\framework-arduinoadafruitnrf52\cores\nRF5\freertos\portable\MemMang\heap_4.c:45:
You only have to define the desired heap size correctly (again: a number) in your FreeRTOSConfig.h. That should be easy to fix.
The size mainly depends on your needs and of course the available free RAM. But the linker will tell you if it the heap doesn’t fit 