Revert "add signal to pointer kinds" (#8066)

lib/ui/pointer.dart

@@ -50,9 +50,6 @@ enum PointerDeviceKind {
   /// A pointer device with a stylus that has been inverted.
   invertedStylus,
 
-  /// A pointer device that uses a pointer signal.
-  signal,
-
   /// An unknown pointer device.
   unknown
 }

lib/ui/window/pointer_data.h

@@ -28,7 +28,6 @@ struct alignas(8) PointerData {
     kMouse,
     kStylus,
     kInvertedStylus,
-    kSignal,
   };
 
   // Must match the PointerSignalKind enum in pointer.dart.

shell/platform/android/io/flutter/view/FlutterView.java

@@ -378,8 +378,7 @@ public class FlutterView extends SurfaceView
     private static final int kPointerDeviceKindMouse = 1;
     private static final int kPointerDeviceKindStylus = 2;
     private static final int kPointerDeviceKindInvertedStylus = 3;
-    private static final int kPointerDeviceKindSignal = 4;
-    private static final int kPointerDeviceKindUnknown = 5;
+    private static final int kPointerDeviceKindUnknown = 4;
 
     // Must match the PointerSignalKind enum in pointer.dart.
     private static final int kPointerSignalKindNone = 0;