Tests: never use System.err

Always print stack traces to System.out, and replace all
System.err.println()'s with System.out.println().

Follow-up of https://android-review.googlesource.com/#/c/187020/ and
https://android-review.googlesource.com/#/c/407032/.

Test: m test-art-host
      m test-art-target
Change-Id: I9ab9cd955a8db25b2ec6673790e5bc924f62c88a
diff --git a/test/044-proxy/src/ConstructorProxy.java b/test/044-proxy/src/ConstructorProxy.java
index 95d150c..dfafbd8 100644
--- a/test/044-proxy/src/ConstructorProxy.java
+++ b/test/044-proxy/src/ConstructorProxy.java
@@ -28,7 +28,7 @@
       new ConstructorProxy().runTest();
     } catch (Exception e) {
       System.out.println("Unexpected failure occured");
-      e.printStackTrace();
+      e.printStackTrace(System.out);
     }
   }