Add API to get KeyCode produced by physical key location.

The physical key location is provided as a location KeyCode pointing to a location on a US keyboard layout.

Bug: 179812917
Test: atest KeyboardLayoutChangeTest
Test: atest android.hardware.input.cts.tests -m
Test: atest inputflinger_tests -m
Change-Id: Ib5ed41890cbbe393ee9ada1a04cbaaf82c9bb1fc
diff --git a/services/inputflinger/reader/mapper/TouchInputMapper.h b/services/inputflinger/reader/mapper/TouchInputMapper.h
index 9fd30e4..c948f56 100644
--- a/services/inputflinger/reader/mapper/TouchInputMapper.h
+++ b/services/inputflinger/reader/mapper/TouchInputMapper.h
@@ -138,7 +138,7 @@
     explicit TouchInputMapper(InputDeviceContext& deviceContext);
     ~TouchInputMapper() override;
 
-    uint32_t getSources() override;
+    uint32_t getSources() const override;
     void populateDeviceInfo(InputDeviceInfo* deviceInfo) override;
     void dump(std::string& dump) override;
     void configure(nsecs_t when, const InputReaderConfiguration* config, uint32_t changes) override;