[REEF-1648] Allow transition from ALLOCATED to RUNNING in EvaluatorState

JIRA:
  [REEF-1648](https://issues.apache.org/jira/browse/REEF-1648)

Pull request:
  This closes #1164
diff --git a/lang/java/reef-common/src/main/java/org/apache/reef/runtime/common/driver/evaluator/EvaluatorState.java b/lang/java/reef-common/src/main/java/org/apache/reef/runtime/common/driver/evaluator/EvaluatorState.java
index 6ee80a8..e3ce10f 100644
--- a/lang/java/reef-common/src/main/java/org/apache/reef/runtime/common/driver/evaluator/EvaluatorState.java
+++ b/lang/java/reef-common/src/main/java/org/apache/reef/runtime/common/driver/evaluator/EvaluatorState.java
@@ -122,6 +122,9 @@
     case ALLOCATED:
       switch(toState) {
       case SUBMITTED:
+      // direct transition to RUNNING can happen in case of driver restart,
+      // when driver gets heartbeat from evaluator with running task but didn't submit task to it
+      case RUNNING:
       case CLOSING:
       case DONE:
       case FAILED: