Fix crash when array is null

app/src/main/java/net/pokeranalytics/android/model/utils/FavoriteSessionFinder.kt

@@ -68,7 +68,7 @@ class FavoriteSessionFinder {
 
     companion object {
 
-        private val FAVORITE_SIGNIFICANT_SESSIONS = 15L
+        private const val FAVORITE_SIGNIFICANT_SESSIONS = 15L
 
         /**
          * Copies the favorite session parameters on the [newSession]
@@ -94,7 +94,6 @@ class FavoriteSessionFinder {
                     }
                 }
             }
-
         }
 
         /**
@@ -123,7 +122,7 @@ class FavoriteSessionFinder {
             }
 
             val sortedCounters = counters.values.sortedBy { it.counter }
-            return sortedCounters.first().session
+            return sortedCounters.firstOrNull()?.session
         }
 
     }