Merge pull request google#21 from Lukas-Stuehrk/FixStringComparison

Fixed a string comparison.

Author: btco

android/src/main/java/com/google/samples/apps/iosched/model/ScheduleItem.java

@@ -85,7 +85,7 @@ public boolean equals(Object o) {
         }
         ScheduleItem i = (ScheduleItem) o;
         return type == i.type &&
-                sessionId == i.sessionId &&
+                sessionId.equals(i.sessionId) &&
                 startTime == i.startTime &&
                 endTime == i.endTime;
     }