Record last keypress timestamp on physical keyboard while typing

Added method to record keypress timestamp while typing. This will be
used by touchpad to trigger additional palm rejection logic.

Bug: 301055381
Test: atest KeyboardInputMapperUnitTest
Change-Id: I4bbfe4c5fefc687a4901e46c9d4c6f832ec1a245
diff --git a/services/inputflinger/reader/mapper/KeyboardInputMapper.cpp b/services/inputflinger/reader/mapper/KeyboardInputMapper.cpp
index 531fc67..f068cc8 100644
--- a/services/inputflinger/reader/mapper/KeyboardInputMapper.cpp
+++ b/services/inputflinger/reader/mapper/KeyboardInputMapper.cpp
@@ -270,7 +270,7 @@
             keyDown.flags = flags;
             mKeyDowns.push_back(keyDown);
         }
-        onKeyDownProcessed();
+        onKeyDownProcessed(downTime);
     } else {
         // Remove key down.
         if (keyDownIndex) {
@@ -448,8 +448,9 @@
     return out;
 }
 
-void KeyboardInputMapper::onKeyDownProcessed() {
+void KeyboardInputMapper::onKeyDownProcessed(nsecs_t downTime) {
     InputReaderContext& context = *getContext();
+    context.setLastKeyDownTimestamp(downTime);
     if (context.isPreventingTouchpadTaps()) {
         // avoid pinging java service unnecessarily, just fade pointer again if it became visible
         context.fadePointer();