Change >= to > in OldSystemTest.test_gc

Test no longer will pass if no GC happens.

Bug: 21440428

Change-Id: I9fd0a4b5e249ab7b47d6f8e339a4f6a059af7426
diff --git a/luni/src/test/java/libcore/java/lang/OldSystemTest.java b/luni/src/test/java/libcore/java/lang/OldSystemTest.java
index 5a9fc2e..93b06c8 100644
--- a/luni/src/test/java/libcore/java/lang/OldSystemTest.java
+++ b/luni/src/test/java/libcore/java/lang/OldSystemTest.java
@@ -267,7 +267,7 @@
         long afterGC = rt.totalMemory() - rt.freeMemory();
         assertTrue("memory was not released after calling System.gc()." +
                 "before gc: " + beforeGC + "; after gc: " + afterGC,
-                beforeGC >= afterGC);
+                beforeGC > afterGC);
     }
 
     public void test_getenv() {