refactor(ivy): ngcc - use .has() to check Map membership (#25445)

Previously we were relying upon the `.get()` method to return `undefined`
but it is clearer and safer to always check with `.has()` first.

PR Close #25445

packages/compiler-cli/ngcc/src/analysis/module_with_providers_analyzer.ts

@@ -63,7 +63,7 @@ export class ModuleWithProvidersAnalyzer {
             ngModule = {node: dtsNgModule, viaModule: null};
           }
           const dtsFile = dtsFn.getSourceFile();
-          const analysis = analyses.get(dtsFile) || [];
+          const analysis = analyses.has(dtsFile) ? analyses.get(dtsFile) : [];
           analysis.push({declaration: dtsFn, ngModule});
           analyses.set(dtsFile, analysis);
         }