Address review comments

src/helpers/ExternalWatchdogManager.h

@@ -1,10 +1,10 @@
 #pragma once
 
-class ExWatchdogManager {
+class ExternalWatchdogManager {
 protected:
   unsigned long next_feed_watchdog;
 public:
-  ExWatchdogManager() { next_feed_watchdog = 0; }
+  ExternalWatchdogManager() { next_feed_watchdog = 0; }
   virtual bool begin() { return false; }
   virtual void loop() { }
   virtual unsigned long getIntervalMs() const { return 0; }