Create Input SlopController

Create a basic input slop controller, and use it for rotary inputs.

Bug: 285957835
Test: atest SlopControllerTest

Change-Id: I0cabfed1f064b849f8151f069e1241292cc374cf
diff --git a/services/inputflinger/reader/Android.bp b/services/inputflinger/reader/Android.bp
index b0edb57..a896d26 100644
--- a/services/inputflinger/reader/Android.bp
+++ b/services/inputflinger/reader/Android.bp
@@ -52,6 +52,7 @@
         "mapper/RotaryEncoderInputMapper.cpp",
         "mapper/SensorInputMapper.cpp",
         "mapper/SingleTouchInputMapper.cpp",
+        "mapper/SlopController.cpp",
         "mapper/SwitchInputMapper.cpp",
         "mapper/TouchCursorInputMapperCommon.cpp",
         "mapper/TouchInputMapper.cpp",