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();

firmware/Test/Board/watch.cpp

@@ -31,11 +31,13 @@ using namespace BSP::Schedule;
 LowPowerTaskScheduler<10> g_sched;
 GpioDriver g_gpioa(GPIOA);
 UsartDriver g_test_uart(USART2, g_sched);
+GpioPin g_debug0_pin(g_gpioa, 3);
 static GpioPin g_tx_pin(g_gpioa, 9);
 
 void board_init() {
     g_gpioa.enable();
     g_tx_pin.configure_alternate_function(4);
+    g_debug0_pin.configure_input(GpioDriver::input_pull_t::PULL_UP);
     g_test_uart.init();
 
     RtcDriver::init();