Make run test 572-checker-array-get-regression gcstress friendly.

The large array allocated in
test/572-checker-array-get-regression/src/Main.java used to
be too big for the small heap used in gcstress mode.  Use a
smaller array size that however still exercises the initial
issue checked by this regression test.

Bug: 26817006
Bug: 12687968
Change-Id: Id7080a18007cad9b5d4ac31b45f7df46213a908e
diff --git a/test/572-checker-array-get-regression/expected.txt b/test/572-checker-array-get-regression/expected.txt
index c08d783..f7d1ad4 100644
--- a/test/572-checker-array-get-regression/expected.txt
+++ b/test/572-checker-array-get-regression/expected.txt
@@ -1 +1 @@
-1048575
+524287