Use NamedEnum for printing Entry type

Currently, we are using InputMessage::typeToString, a manually written
function, to print the entry type.

Let's use "NamedEnum" instead to simplify the process of adding new
types.

Bug: 167947340
Test: compile only
Change-Id: I26d0a469bf93adbe2795d8a378c25e6ded891274
diff --git a/services/inputflinger/host/InputFlinger.h b/services/inputflinger/host/InputFlinger.h
index 47773d9..8112038 100644
--- a/services/inputflinger/host/InputFlinger.h
+++ b/services/inputflinger/host/InputFlinger.h
@@ -43,19 +43,19 @@
 
     InputFlinger() ANDROID_API;
 
-    virtual status_t dump(int fd, const Vector<String16>& args);
+    status_t dump(int fd, const Vector<String16>& args) override;
     binder::Status setInputWindows(const std::vector<InputWindowInfo>&,
-                                   const sp<ISetInputWindowsListener>&) {
+                                   const sp<ISetInputWindowsListener>&) override {
         return binder::Status::ok();
     }
-    binder::Status createInputChannel(const std::string&, InputChannel*) {
+    binder::Status createInputChannel(const std::string&, InputChannel*) override {
         return binder::Status::ok();
     }
-    binder::Status removeInputChannel(const sp<IBinder>&) { return binder::Status::ok(); }
-    binder::Status setFocusedWindow(const FocusRequest&) { return binder::Status::ok(); }
+    binder::Status removeInputChannel(const sp<IBinder>&) override { return binder::Status::ok(); }
+    binder::Status setFocusedWindow(const FocusRequest&) override { return binder::Status::ok(); }
 
 private:
-    virtual ~InputFlinger();
+    ~InputFlinger() override;
 
     void dumpInternal(String8& result);