fixed the issue of ddm (#2239)

* fixed the issue of ddm

* fixed the ddm issue

* updated test and ploicyvaluebtdefault as true

* fixed test

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Co-authored-by: Sakshi Gupta <sakshig@microsoft.com>

src/Explorer/Tree/Collection.ts

@@ -141,7 +141,7 @@ export default class Collection implements ViewModels.Collection {
     const defaultDataMaskingPolicy: DataModels.DataMaskingPolicy = {
       includedPaths: Array<{ path: string; strategy: string; startPosition: number; length: number }>(),
       excludedPaths: Array<string>(),
-      isPolicyEnabled: false,
+      isPolicyEnabled: true,
     };
     const observablePolicy = ko.observable(data.dataMaskingPolicy || defaultDataMaskingPolicy);
     observablePolicy.subscribe(() => {});