Refactor use of services in InputMappers.

Create InputDeviceContext class to hide direct EventHub and
InputDevice accesses from InputMappers.

Test: atest inputflinger_tests libinput_tests
Change-Id: I05f9c808fc1a6f4c9207bd29fde50b76ec5655bb
diff --git a/services/inputflinger/reader/mapper/SwitchInputMapper.h b/services/inputflinger/reader/mapper/SwitchInputMapper.h
index e65d4e2..4d74163 100644
--- a/services/inputflinger/reader/mapper/SwitchInputMapper.h
+++ b/services/inputflinger/reader/mapper/SwitchInputMapper.h
@@ -23,7 +23,7 @@
 
 class SwitchInputMapper : public InputMapper {
 public:
-    explicit SwitchInputMapper(InputDevice* device);
+    explicit SwitchInputMapper(InputDeviceContext& deviceContext);
     virtual ~SwitchInputMapper();
 
     virtual uint32_t getSources() override;