Replace String.valueOf(true) with "true" literal

String.valueOf(true) is unnecessarily verbose and incurs a method
call. A string literal is clearer and avoids unnecessary overhead.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Author: laeubi

ui/org.eclipse.pde.ui/src/org/eclipse/pde/internal/ui/correction/UpdateSingletonToSymbolicName.java

@@ -42,7 +42,7 @@ protected void createChange(BundleModel model) {
 				int ind2 = entry.indexOf(':');
 				String invalidDir = entry.substring(ind1 + 1, ind2);
 				((BundleSymbolicNameHeader) header).setDirective(invalidDir, null);
-				((BundleSymbolicNameHeader) header).setDirective(Constants.SINGLETON_DIRECTIVE, String.valueOf(true));
+				((BundleSymbolicNameHeader) header).setDirective(Constants.SINGLETON_DIRECTIVE, "true"); //$NON-NLS-1$
 			}
 		}
 	}