[Autofill Assistant] Fix initial bottomsheet size.

This CL fixes a bug in the bottom sheet where size change notifications while in SCROLLING state where ignored. See the linked bug for more information.

Bug: b/144838045
Change-Id: I825ed22c2078873fcf7295f86e99d4b14b01cc56
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1926479Reviewed-by: Matthew Jones <mdjones@chromium.org>
Reviewed-by: Mathias Carlen <mcarlen@chromium.org>
Commit-Queue: Clemens Arbesser <arbesser@google.com>
Cr-Commit-Position: refs/heads/master@{#717600}

chrome/android/java/src/org/chromium/chrome/browser/widget/bottomsheet/BottomSheet.java

@@ -1125,7 +1125,14 @@ class BottomSheet extends FrameLayout
      * Called when the sheet content size changed.
      */
     private void onContentSizeChanged(int width, int height, int oldWidth, int oldHeight) {
+        boolean heightChanged = mContentDesiredHeight != height;
         mContentDesiredHeight = height;
+
+        if (heightChanged && mCurrentState == SheetState.SCROLLING) {
+            endAnimations();
+            return;
+        }
+
         ensureContentIsWrapped(/* animate= */ false);
     }