[Incubator.Slider] Fix Android hitSlop on thumb (#3967)

Added .hitSlop() to the RNGH Gesture.Pan() on the thumb so the gesture
handler natively recognizes touches in the expanded hit area on Android.
Also added hitSlop to the Pan gesture mock in jest setup.

Co-authored-by: Claude Sonnet 4.6 <noreply@anthropic.com>

Author: adids1221

packages/react-native-ui-lib/jestSetup/jest-setup.js

@@ -77,6 +77,7 @@ jest.mock('react-native-gesture-handler',
       PanMock.onFinalize = getDefaultMockedHandler('onFinalize');
       PanMock.activateAfterLongPress = getDefaultMockedHandler('activateAfterLongPress');
       PanMock.enabled = getDefaultMockedHandler('enabled');
+      PanMock.hitSlop = getDefaultMockedHandler('hitSlop');
       PanMock.onTouchesMove = getDefaultMockedHandler('onTouchesMove');
       PanMock.prepare = jest.fn();
       PanMock.initialize = jest.fn();

packages/react-native-ui-lib/src/incubator/slider/Thumb.tsx

@@ -62,6 +62,7 @@ const Thumb = (props: ThumbProps) => {
   const lastOffset = useSharedValue(0);
 
   const gesture = Gesture.Pan()
+    .hitSlop(hitSlop)
     .onBegin(() => {
       onSeekStart?.();
       isPressed.value = true;