fix: handle correctly the situation when the compilation hash is the same as the previous one

Currently CLI considers the hash that is the same as the previous as invalid and this way the application is restarted on device. As that hash is already handled, we should consider it as a valid hash.
Steps to reproduce :
```
`tns create ts_proj`  - choose ts tabs project

npm i tns-core-modules@rc --save --save-exact

npm i nativescript-dev-webpack@rc --save-dev --save-exact

node_modules/.bin/update-ns-webpack --deps –configs

tns run android

Change something in app.android.scss - the change is applied, no restart

Change something in app.ios.scss - application restarts
```

Author: Fatme

lib/services/webpack/webpack-compiler-service.ts

@@ -260,7 +260,10 @@ export class WebpackCompilerService extends EventEmitter implements IWebpackComp
 		// if files will be emitted or not. This way, the first successful compilation after fixing the compilation error generates
 		// a hash that is not the same as the one expected in the latest emitted hot-update.json file.
 		// As a result, the hmr chain is broken and the changes are not applied.
-		const isHashValid = nextHash ? this.expectedHashes[platform] === currentHash : true;
+		let isHashValid = nextHash ? this.expectedHashes[platform] === currentHash : true;
+		if (this.expectedHashes[platform] === nextHash) {
+			isHashValid = true;
+		}
 		this.expectedHashes[platform] = nextHash;
 
 		const emittedHotUpdatesAndAssets = isHashValid ? _.difference(allEmittedFiles, chunkFiles) : allEmittedFiles;

test/services/webpack/webpack-compiler-service.ts

@@ -86,5 +86,12 @@ describe("WebpackCompilerService", () => {
 			const androidResult = webpackCompilerService.getUpdatedEmittedFiles(getAllEmittedFiles("hash6"), chunkFiles, "hash8", androidPlatformName);
 			assert.deepEqual(androidResult.emittedFiles, ["bundle.hash6.hot-update.js", "hash6.hot-update.json"]);
 		});
+		it("should return only emitted files when the compilation hash is the same as the previous one", () => {
+			const initiallyEmittedFiles = ['bundle.js', 'runtime.js', 'vendor.js', 'fonts/FontAwesome.ttf', 'package.json', 'tns-java-classes.js' ];
+			webpackCompilerService.getUpdatedEmittedFiles(initiallyEmittedFiles, chunkFiles, "hash1", iOSPlatformName);
+			const result = webpackCompilerService.getUpdatedEmittedFiles(["bundle.js"], chunkFiles, "hash1", iOSPlatformName);
+
+			assert.deepEqual(result.emittedFiles, []);
+		});
 	});
 });