Default button polarity to active-LOW across all firmware types

Nearly all LoRa boards use a boot button that pulls to ground when
pressed.

variants/t1000-e/platformio.ini

@@ -10,7 +10,6 @@ build_flags = ${nrf52_base.build_flags}
   -I src/helpers/ui
   -D T1000_E
   -D PIN_USER_BTN=6
-  -D USER_BTN_PRESSED=HIGH
   -D PIN_STATUS_LED=24
   -D RADIO_CLASS=CustomLR1110
   -D WRAPPER_CLASS=CustomLR1110Wrapper