[Android][TouchToFill] Prevent double-dismissing the bottom sheet

If the touch to fill sheet is dismissed, it triggers a second call to
BottomSheetController#hideContent.

That call triggers an observer in the BottomContainer again which then
moves itself out of the visible view port.
(The latter can only happen since a division by zero bypasses some guard
conditions. It might make sense to abort attempts at repeatedly
dismissing the bottomsheet but this exceeds the scope of this CL.)

Bug: 1021550
Change-Id: Ida2b6bc9ffd18513419bed40b29ca84528310907
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1899882Reviewed-by: Jan Wilken Dörrie <jdoerrie@chromium.org>
Commit-Queue: Friedrich [CET] <fhorschig@chromium.org>
Cr-Commit-Position: refs/heads/master@{#712703}

chrome/browser/touch_to_fill/android/internal/java/src/org/chromium/chrome/browser/touch_to_fill/TouchToFillView.java

@@ -82,7 +82,7 @@ class TouchToFillView implements BottomSheetContent {
         if (isVisible) {
             mBottomSheetController.addObserver(mBottomSheetObserver);
             mBottomSheetController.requestShowContent(this, true);
-        } else {
+        } else if (mBottomSheetController.isSheetOpen()) {
             mBottomSheetController.hideContent(this, true);
         }
     }