use async/wait version for reading file

Author: Mihail Slavchev

lib/services/android-project-service.ts

@@ -198,7 +198,7 @@ class AndroidProjectService implements IPlatformProjectService {
     private getProjectReferences(projDir: string): ILibRef[]{
         var projProp = path.join(projDir, "project.properties");
 
-        var lines = fs.readFileSync(projProp, { encoding: "utf-8" }).split(os.EOL);
+		var lines = this.$fs.readText(projProp, "utf-8").wait().split(os.EOL);
 
         var refs: ILibRef[] = [];