Convert TouchInputMapper enums to enum classes.

Also, drop virtual for override methods. The override keyword requires
a method to both be virtual and overriding a parent's virtual method, so
having both is redundant.

Bug: 160010896
Test: atest InputReader_test.cpp
Change-Id: Ia36e0fa95068531e5e23c3932b7c190dfa40ecd9
diff --git a/services/inputflinger/reader/mapper/MultiTouchInputMapper.h b/services/inputflinger/reader/mapper/MultiTouchInputMapper.h
index 89ef41d..190282f 100644
--- a/services/inputflinger/reader/mapper/MultiTouchInputMapper.h
+++ b/services/inputflinger/reader/mapper/MultiTouchInputMapper.h
@@ -92,15 +92,15 @@
 class MultiTouchInputMapper : public TouchInputMapper {
 public:
     explicit MultiTouchInputMapper(InputDeviceContext& deviceContext);
-    virtual ~MultiTouchInputMapper();
+    ~MultiTouchInputMapper() override;
 
-    virtual void reset(nsecs_t when) override;
-    virtual void process(const RawEvent* rawEvent) override;
+    void reset(nsecs_t when) override;
+    void process(const RawEvent* rawEvent) override;
 
 protected:
-    virtual void syncTouch(nsecs_t when, RawState* outState);
-    virtual void configureRawPointerAxes();
-    virtual bool hasStylus() const;
+    void syncTouch(nsecs_t when, RawState* outState) override;
+    void configureRawPointerAxes() override;
+    bool hasStylus() const override;
 
 private:
     MultiTouchMotionAccumulator mMultiTouchMotionAccumulator;