InputMapper refactor: Change readerconfig pointer to const ref

We are refactoring Input-mapper to ensure they are configured at the
time of initialisation.

In this CL we are changing InputReaderConfiguration raw pointer to
a const reference and rename it to readerConfig for clarity.

Test: build, inputflinger_tests, presubmit checks

Bug: 256009910
Change-Id: Iae22c8cfba836bd311a51fca13d680456a61e604
diff --git a/services/inputflinger/tests/FakeInputReaderPolicy.h b/services/inputflinger/tests/FakeInputReaderPolicy.h
index 28ac505..85ff01a 100644
--- a/services/inputflinger/tests/FakeInputReaderPolicy.h
+++ b/services/inputflinger/tests/FakeInputReaderPolicy.h
@@ -63,7 +63,7 @@
     void addDisabledDevice(int32_t deviceId);
     void removeDisabledDevice(int32_t deviceId);
     void setPointerController(std::shared_ptr<FakePointerController> controller);
-    const InputReaderConfiguration* getReaderConfiguration() const;
+    const InputReaderConfiguration& getReaderConfiguration() const;
     const std::vector<InputDeviceInfo>& getInputDevices() const;
     TouchAffineTransformation getTouchAffineTransformation(const std::string& inputDeviceDescriptor,
                                                            ui::Rotation surfaceRotation);