Code layout cleanup

- Fwd declare where possible
- List .h first in the .cpp to verify proper includes
- Remove hacky -internal.h file and move testBitInRange to a new component

Change-Id: I442248c4b32738c6c2af250f45d4c8822c862e08
diff --git a/modules/input/evdev/InputMapper.h b/modules/input/evdev/InputMapper.h
index b33cb63..5e88d06 100644
--- a/modules/input/evdev/InputMapper.h
+++ b/modules/input/evdev/InputMapper.h
@@ -17,11 +17,16 @@
 #ifndef ANDROID_INPUT_MAPPER_H_
 #define ANDROID_INPUT_MAPPER_H_
 
-#include "InputHost.h"
-#include "InputHub.h"
+struct input_device_handle;
 
 namespace android {
 
+class InputDeviceNode;
+class InputReport;
+class InputReportDefinition;
+struct InputEvent;
+using InputDeviceHandle = struct input_device_handle;
+
 /**
  * An InputMapper processes raw evdev input events and combines them into
  * Android input HAL reports. A given InputMapper will focus on a particular
@@ -31,7 +36,8 @@
  */
 class InputMapper {
 public:
-    virtual ~InputMapper() = default;
+    InputMapper() = default;
+    virtual ~InputMapper() {}
 
     /**
      * If the mapper supports input events from the InputDevice,