[Android][BottomSheet] Handle internal states for thresholds

Unfortunate timing may lead the threshold calculation to request a
height for an internal state (e.g. calling expand() right after
requestShowContent() before the animation finishes).

Transition from/to internal states should always succeed, so consider a
threshold cleared if one of the states in transition is internal.

Bug: 1028783
Change-Id: I8650845c23e1ba9f13fd8c79c7e021637d824777
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1939414
Commit-Queue: Friedrich [CET] <fhorschig@chromium.org>
Auto-Submit: Friedrich [CET] <fhorschig@chromium.org>
Reviewed-by: Matthew Jones <mdjones@chromium.org>
Cr-Commit-Position: refs/heads/master@{#721056}

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

@@ -1030,6 +1030,8 @@ class BottomSheet extends FrameLayout
     private boolean hasCrossedThresholdToNextState(
             @SheetState int prev, @SheetState int next, float sheetHeight, boolean sheetMovesDown) {
         if (next == prev) return false;
+        // Moving from an internal/temporary state always works:
+        if (prev == SheetState.NONE || prev == SheetState.SCROLLING) return true;
         float lowerBound = getSheetHeightForState(prev);
         float distance = getSheetHeightForState(next) - lowerBound;
         return Math.abs((sheetHeight - lowerBound) / distance)