Merge "Improve error message in WMS#isInTouchMode" into udc-dev

        synchronized (mGlobalLock) {

            final DisplayContent displayContent = mRoot.getDisplayContent(displayId);

            if (displayContent == null) {

                throw new IllegalStateException("No touch mode is defined for displayId {"

                        + displayId + "}");

                throw new IllegalStateException("Failed to retrieve the touch mode state for"

                        + "display {" + displayId + "}: display is not registered in "

                        + "WindowRootContainer");

            }

            return displayContent.isInTouchMode();

        }