Fix missing assertFalse import in test

Co-authored-by: laeubi <1331477+laeubi@users.noreply.github.com>

Author: Copilot

resources/tests/org.eclipse.core.tests.resources/src/org/eclipse/core/tests/internal/resources/HierarchicalProjectPreferencesTest.java

@@ -18,6 +18,7 @@
 import static org.eclipse.core.tests.resources.ResourceTestUtil.createTestMonitor;
 import static org.eclipse.core.tests.resources.ResourceTestUtil.createUniqueString;
 import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertFalse;
 import static org.junit.Assert.assertNull;
 
 import org.eclipse.core.resources.IProject;