[Bottom Sheet] Prevents nested scroll from occurring in a scroll sess…

…ion when the bottom sheet is already being resized.

Previously, the bottom sheet could be fixed at any height while resizing it by triggering a fling in the opposite direction.

PiperOrigin-RevId: 628170687

lib/java/com/google/android/material/bottomsheet/BottomSheetBehavior.java

@@ -748,7 +748,10 @@ public void onNestedPreScroll(
  int currentTop = child.getTop();
  int newTop = currentTop - dy;
  if (dy > 0) { // Upward swipe
- if (!draggableOnNestedScroll && target == scrollingChild && target.canScrollVertically(1)) {
+ if (!nestedScrolled
+ && !draggableOnNestedScroll
+ && target == scrollingChild
+ && target.canScrollVertically(1)) {
  // Prevent dragging if draggableOnNestedScroll=false and we can scroll the scrolling child.
  draggableOnNestedScrollLastDragIgnored = true;
  return;
@@ -769,7 +772,7 @@ public void onNestedPreScroll(
  }
  } else if (dy < 0) { // Downward swipe
  boolean canScrollUp = target.canScrollVertically(-1);
- if (!draggableOnNestedScroll && target == scrollingChild && canScrollUp) {
+ if (!nestedScrolled && !draggableOnNestedScroll && target == scrollingChild && canScrollUp) {
  // Prevent dragging if draggableOnNestedScroll=false and we can scroll the scrolling child.
  draggableOnNestedScrollLastDragIgnored = true;
  return;