Verify the main app mostly sleeps

This validates that the main watch app spends at
least 99.5% of it's time sleeping in the first 10
seconds.

firmware/Test/Board/devboard.cpp

@@ -32,6 +32,7 @@ using namespace BSP::Schedule;
 LowPowerTaskScheduler<10> g_sched;
 GpioDriver g_gpioa(GPIOA);
 UsartDriver g_test_uart(USART1, g_sched);
+GpioPin g_debug0_pin(g_gpioa, 4);
 
 void board_init() {
     g_gpioa.enable();