Merge "Fix null dereference in WMShell transition" into main

                Log.e(TAG, "Got duplicate transitionReady for " + transitionToken);

                // The transition is already somewhere else in the pipeline, so just return here.

                t.apply();

                if (existing.mFinishT != null) {

                    existing.mFinishT.merge(finishT);

                } else {

                    existing.mFinishT = finishT;

                }

                return;

            }

            // This usually means the system is in a bad state and may not recover; however,