Merge "Delay visible of rotation enter animation" into main

    private void postProcessRotationAnimation(@NonNull AnimationSet enterAnim,

            @NonNull AnimationSet exitAnim, int rotationDelta) {

        int alphaAnimIndex = -1;

        long enterClipDuration = 0;

        long enterClipStartOffset = 0;

        final var enterAnimations = enterAnim.getAnimations();

                // Use half duration to avoid showing blank area too long.

                enterClipDuration = anim.getDuration() / 2;

                enterClipStartOffset = anim.getStartOffset() / 2;

                alphaAnimIndex = i;

                // TODO(b/438615184): Update screen_rotate_*_enter.xml.

                // Use an instant alpha animation to delay the enter surface from being visible

                // when it is almost occluded by the exit surface. That may reduce some cost of

                // layer composition.

                anim.setDuration(10);

                anim.setStartOffset(enterClipStartOffset);

                break;

            }

        }

        // TODO(b/438615184): Remove alpha animation from screen_rotate_*_enter.xml.

        if (alphaAnimIndex >= 0) {

            enterAnimations.remove(alphaAnimIndex);

        }

        if (rotationDelta % 2 == 0) {

            // 180 degree delta doesn't have size change, so no additional effects are needed.

            return;