Remove useOverflowInset flag as we rolled out 100% to public for over three months

Summary:
Remove overflow inset optimization flags as they've been rolled out 100% to public.

Changelog:
[Android][Internal] - Clean up feature flags for overflowInset

Reviewed By: nlutsenko

Differential Revision: D36990986

fbshipit-source-id: 77da78a2927034893f25937c2ccbd0b53e08031d

ReactAndroid/src/main/java/com/facebook/react/uimanager/TouchTargetHelper.java

@@ -19,7 +19,6 @@ import android.view.ViewGroup;
 import androidx.annotation.Nullable;
 import com.facebook.react.bridge.JSApplicationIllegalArgumentException;
 import com.facebook.react.bridge.UiThreadUtil;
-import com.facebook.react.config.ReactFeatureFlags;
 import com.facebook.react.touch.ReactHitSlopView;
 import com.facebook.react.uimanager.common.ViewUtil;
 import java.util.ArrayList;
@@ -192,7 +191,6 @@ public class TouchTargetHelper {
           // If the touch point is outside of the overflowinset for the view, we can safely ignore
           // it.
           if (ViewUtil.getUIManagerType(view.getId()) == FABRIC
-              && ReactFeatureFlags.useOverflowInset
               && !isTouchPointInViewWithOverflowInset(eventCoords[0], eventCoords[1], view)) {
             return null;
           }