Add API to support key remappings on native side

For adding support for modifier key remapping, we need to add
native support save key remappings and send appropriate android
key codes using KeyCharacterMap.

Test: atest KeyboardLayoutChangeTest
Bug: 252812993
Change-Id: Ib3efa866c6e6408dd11e97dfaf49feb92f48bc18
diff --git a/services/inputflinger/reader/include/InputReader.h b/services/inputflinger/reader/include/InputReader.h
index 4f2503a..e9c989a 100644
--- a/services/inputflinger/reader/include/InputReader.h
+++ b/services/inputflinger/reader/include/InputReader.h
@@ -68,6 +68,8 @@
     int32_t getKeyCodeState(int32_t deviceId, uint32_t sourceMask, int32_t keyCode) override;
     int32_t getSwitchState(int32_t deviceId, uint32_t sourceMask, int32_t sw) override;
 
+    void addKeyRemapping(int32_t deviceId, int32_t fromKeyCode, int32_t toKeyCode) const override;
+
     int32_t getKeyCodeForKeyLocation(int32_t deviceId, int32_t locationKeyCode) const override;
 
     void toggleCapsLockState(int32_t deviceId) override;