camera2: Workaround for mockito test failures

Change-Id: I7c169034dc5c90fa97ba1beba115e6292eefad2f
diff --git a/tests/tests/hardware/src/android/hardware/camera2/cts/CameraManagerTest.java b/tests/tests/hardware/src/android/hardware/camera2/cts/CameraManagerTest.java
index 0a28275..6668db0 100644
--- a/tests/tests/hardware/src/android/hardware/camera2/cts/CameraManagerTest.java
+++ b/tests/tests/hardware/src/android/hardware/camera2/cts/CameraManagerTest.java
@@ -73,6 +73,14 @@
     protected void setUp() throws Exception {
         super.setUp();
 
+        /**
+         * Workaround for mockito and JB-MR2 incompatibility
+         *
+         * Avoid java.lang.IllegalArgumentException: dexcache == null
+         * https://code.google.com/p/dexmaker/issues/detail?id=2
+         */
+        System.setProperty("dexmaker.dexcache", getContext().getCacheDir().toString());
+
         mCameraListener = spy(new BlockingStateListener());
 
         mHandlerThread = new HandlerThread(TAG);