Unphone improvements (#172)

- Debounce nav button presses: This fixes multiple triggers on a single press to navigate back. Otherwise, more than 1 app would often close at the same time.
- Nav button respond to release instead of push down, because these buttons aren't super reliable in general. (I might change this in the future after more testing)
- Move single buzz earlier in boot phase, so that we can detect silent boot loops.

Boards/UnPhone/Source/PowerOn.cpp

@@ -64,24 +64,22 @@ static bool unPhonePowerOn() {
 
     unPhoneFeatures.printInfo();
 
+    // Vibrate once
+    // Note: Do this before power switching logic, to detect silent boot loops
+    unPhoneFeatures.setVibePower(true);
+    tt::kernel::delayMillis(150);
+    unPhoneFeatures.setVibePower(false);
+
+    // Turn off the device if power switch is on off state,
+    // instead of waiting for the Thread to start and continue booting
     updatePowerSwitch();
     startPowerSwitchThread();
 
     unPhoneFeatures.setBacklightPower(false);
-
-    // Init touch screen GPIOs (used for vibe motor)
     unPhoneFeatures.setVibePower(false);
-
     unPhoneFeatures.setIrPower(false);
-
-    // This will be default LOW implicitly, but this makes it explicit
     unPhoneFeatures.setExpanderPower(false);
 
-    // Vibrate once
-    unPhoneFeatures.setVibePower(true);
-    tt::kernel::delayMillis(150);
-    unPhoneFeatures.setVibePower(false);
-
     return true;
 }