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/include/InputReaderContext.h b/services/inputflinger/reader/include/InputReaderContext.h
index aed7563..69b2315 100644
--- a/services/inputflinger/reader/include/InputReaderContext.h
+++ b/services/inputflinger/reader/include/InputReaderContext.h
@@ -65,6 +65,9 @@
 
     virtual void setPreventingTouchpadTaps(bool prevent) = 0;
     virtual bool isPreventingTouchpadTaps() = 0;
+
+    virtual void setLastKeyDownTimestamp(nsecs_t when) = 0;
+    virtual nsecs_t getLastKeyDownTimestamp() = 0;
 };
 
 } // namespace android