Updates to SlopController

- Addressed comments in ag/23670464
- Moved the creation of the controller from the rotary input mapper
  constructor, to its `populateDeviceInfo`, since the slop params were
  not being read in the constructor (since the device property map is
  not initialized when the input mapper is created).
- Added logs to note the slop params

Bug: 285957835
Test: atest SlopControllerTest

Change-Id: Id1bd77b52c9d93d30d3d2594662e19ccc40a1bb6
diff --git a/services/inputflinger/reader/mapper/RotaryEncoderInputMapper.h b/services/inputflinger/reader/mapper/RotaryEncoderInputMapper.h
index 4732bcd..fe5d152 100644
--- a/services/inputflinger/reader/mapper/RotaryEncoderInputMapper.h
+++ b/services/inputflinger/reader/mapper/RotaryEncoderInputMapper.h
@@ -47,7 +47,7 @@
     int32_t mSource;
     float mScalingFactor;
     ui::Rotation mOrientation;
-    std::unique_ptr<SlopController> mSlopController = nullptr;
+    std::unique_ptr<SlopController> mSlopController;
 
     explicit RotaryEncoderInputMapper(InputDeviceContext& deviceContext,
                                       const InputReaderConfiguration& readerConfig);