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/tests/input/evdev/Android.mk b/tests/input/evdev/Android.mk
index a79de34..1d8bf43 100644
--- a/tests/input/evdev/Android.mk
+++ b/tests/input/evdev/Android.mk
@@ -5,6 +5,7 @@
 LOCAL_C_INCLUDES += $(TOP)/external/gmock/include
 
 LOCAL_SRC_FILES:= \
+    BitUtils_test.cpp \
     InputDevice_test.cpp \
     InputHub_test.cpp \
     InputMocks.cpp \