InputMapper refactor: TouchInputMapper

Use the factory method for TouchInputMapper(s) to be configured on
initilisation, and make constructors private

Test: atest libinput_tests inputflinger_tests
Bug: 256009910
Change-Id: I3c27cf54795a793b8a9fcaa8f4a5e62fbe02a25a
diff --git a/services/inputflinger/reader/mapper/MultiTouchInputMapper.h b/services/inputflinger/reader/mapper/MultiTouchInputMapper.h
index f300ee1..1d788df 100644
--- a/services/inputflinger/reader/mapper/MultiTouchInputMapper.h
+++ b/services/inputflinger/reader/mapper/MultiTouchInputMapper.h
@@ -27,8 +27,6 @@
     friend std::unique_ptr<T> createInputMapper(InputDeviceContext& deviceContext,
                                                 const InputReaderConfiguration& readerConfig,
                                                 Args... args);
-    explicit MultiTouchInputMapper(InputDeviceContext& deviceContext,
-                                   const InputReaderConfiguration& readerConfig);
 
     ~MultiTouchInputMapper() override;
 
@@ -41,6 +39,8 @@
     bool hasStylus() const override;
 
 private:
+    explicit MultiTouchInputMapper(InputDeviceContext& deviceContext,
+                                   const InputReaderConfiguration& readerConfig);
     // simulate_stylus_with_touch is a debug mode that converts all finger pointers reported by this
     // mapper's touchscreen into stylus pointers, and adds SOURCE_STYLUS to the input device.
     // It is used to simulate stylus events for debugging and testing on a device that does not