TouchpadInputMapper: add dump method

This dumps the state from the gesture converter, and a list of gesture
properties, which is useful for debugging settings.

Bug: 251196347
Test: run dumpsys input with touchpad connected, check output
Change-Id: I036d0251b06489b645b883a239ff345a98448497
diff --git a/services/inputflinger/reader/mapper/TouchpadInputMapper.cpp b/services/inputflinger/reader/mapper/TouchpadInputMapper.cpp
index 89ba07e..b6313a1 100644
--- a/services/inputflinger/reader/mapper/TouchpadInputMapper.cpp
+++ b/services/inputflinger/reader/mapper/TouchpadInputMapper.cpp
@@ -19,6 +19,7 @@
 #include <optional>
 
 #include <android/input.h>
+#include <input/PrintTools.h>
 #include <linux/input-event-codes.h>
 #include <log/log_main.h>
 #include "TouchCursorInputMapperCommon.h"
@@ -124,6 +125,14 @@
     return AINPUT_SOURCE_MOUSE | AINPUT_SOURCE_TOUCHPAD;
 }
 
+void TouchpadInputMapper::dump(std::string& dump) {
+    dump += INDENT2 "Touchpad Input Mapper:\n";
+    dump += INDENT3 "Gesture converter:\n";
+    dump += addLinePrefix(mGestureConverter.dump(), INDENT4);
+    dump += INDENT3 "Gesture properties:\n";
+    dump += addLinePrefix(mPropertyProvider.dump(), INDENT4);
+}
+
 std::list<NotifyArgs> TouchpadInputMapper::configure(nsecs_t when,
                                                      const InputReaderConfiguration* config,
                                                      uint32_t changes) {