Initial InputMappers for evdev input HAL.

The previous design of the InputHost wrapper classes made it very
painful to do testing, so this change also reverts to a more classical
C++ pattern for non-copyable objects. The InputHost classes still simply
call through to the input_host_t and callbacks as before.

Updated unittests to use gmock for mocking the InputHost interactions.

Change-Id: I4b70df2c89ed48af77446b8f5b87a4bde94510bf
diff --git a/modules/input/evdev/Android.mk b/modules/input/evdev/Android.mk
index d3c49e7..b12867c 100644
--- a/modules/input/evdev/Android.mk
+++ b/modules/input/evdev/Android.mk
@@ -21,7 +21,9 @@
     InputHub.cpp \
     InputDevice.cpp \
     InputDeviceManager.cpp \
-    InputHost.cpp
+    InputHost.cpp \
+    InputMapper.cpp \
+    SwitchInputMapper.cpp
 
 LOCAL_SHARED_LIBRARIES := \
     libhardware_legacy \