Added code to intent unit tests to pre-emptively unbind ID generator to avoid cascading failures.

Change-Id: I2e5aff44a90ceeaaad71d7154b79f20edab620a7
diff --git a/core/net/src/test/java/org/onosproject/net/intent/impl/compiler/LinkCollectionOptimizationTest.java b/core/net/src/test/java/org/onosproject/net/intent/impl/compiler/LinkCollectionOptimizationTest.java
index b0465f0..01b86ba 100644
--- a/core/net/src/test/java/org/onosproject/net/intent/impl/compiler/LinkCollectionOptimizationTest.java
+++ b/core/net/src/test/java/org/onosproject/net/intent/impl/compiler/LinkCollectionOptimizationTest.java
@@ -65,6 +65,7 @@
                 .andReturn(appId);
         sut.coreService = coreService;
 
+        Intent.unbindIdGenerator(idGenerator);
         Intent.bindIdGenerator(idGenerator);
 
         intentExtensionService = createMock(IntentExtensionService.class);