Fix CancellationException stack trace

[mfateev]

When an activity is cancelled the thrown CancellationException contains stack trace of the handleActivityTaskCanceled, not the caller of the activity:

[{"detailMessage":null,"stackTrace":"com.uber.cadence.internal.replay.ActivityDecisionContext.handleActivityTaskCanceled(ActivityDecisionContext.java:134)
com.uber.cadence.internal.replay.DecisionContextImpl.handleActivityTaskCanceled(DecisionContextImpl.java:280)
com.uber.cadence.internal.replay.ReplayDecider.processEvent(ReplayDecider.java:113)
com.uber.cadence.internal.replay.ReplayDecider.decideImpl(ReplayDecider.java:407)
com.uber.cadence.internal.replay.ReplayDecider.decide(ReplayDecider.java:359)
com.uber.cadence.internal.replay.ReplayDecisionTaskHandler.processDecision(ReplayDecisionTaskHandler.java:145)
com.uber.cadence.internal.replay.ReplayDecisionTaskHandler.handleDecisionTaskImpl(ReplayDecisionTaskHandler.java:125)
com.uber.cadence.internal.replay.ReplayDecisionTaskHandler.handleDecisionTask(ReplayDecisionTaskHandler.java:86)
com.uber.cadence.internal.worker.WorkflowWorker$TaskHandlerImpl.handle(WorkflowWorker.java:257)
com.uber.cadence.internal.worker.WorkflowWorker$TaskHandlerImpl.handle(WorkflowWorker.java:229)
com.uber.cadence.internal.worker.PollTaskExecutor.lambda$process$0(PollTaskExecutor.java:71)
java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
java.lang.Thread.run(Thread.java:748)
","suppressedExceptions":[],"class":"java.util.concurrent.CancellationException"}],