Don't run ICU tests on gcstress.

Also fix logic around boolean checks (thanks bash).

bug: 78228743
Test: run-libcore-tests
Change-Id: I2fc2310e9328c0f4b24a281599d51a46336369a9
diff --git a/tools/run-libcore-tests.sh b/tools/run-libcore-tests.sh
index 7f0383d..26b5c0a 100755
--- a/tools/run-libcore-tests.sh
+++ b/tools/run-libcore-tests.sh
@@ -77,7 +77,6 @@
                   "libcore.javax.security"
                   "libcore.javax.sql"
                   "libcore.javax.xml"
-                  "libcore.libcore.icu"
                   "libcore.libcore.io"
                   "libcore.libcore.net"
                   "libcore.libcore.reflect"
@@ -154,11 +153,14 @@
 vogar_args="$vogar_args --vm-arg -Xusejit:$use_jit"
 
 # gcstress may lead to timeouts, so we need dedicated expectations files for it.
-if [[ $gcstress ]]; then
+if $gcstress; then
   expectations="$expectations --expectations art/tools/libcore_gcstress_failures.txt"
-  if [[ $debug ]]; then
+  if $debug; then
     expectations="$expectations --expectations art/tools/libcore_gcstress_debug_failures.txt"
   fi
+else
+  # We only run this package when not under gcstress as it can cause timeouts. See b/78228743.
+  working_packages+=("libcore.libcore.icu")
 fi
 
 # Disable network-related libcore tests that are failing on the following