create a single html view for multiple partial views in angularjs

You could use ng-switch to conditionally render your productList with an include, depending on the route parameters.

Try this in your config:

    angular.module('productapp', [])
      .config(['$routeProvider', function($routeProvider) {
      $routeProvider
        .when('/productapp', {templateUrl: 'partials/productList.html', controller: productsCtrl})
        .when('/productapp/:productId', {templateUrl: 'partials/productList.html', controller: productsCtrl})
        .otherwise({redirectTo: '/productapp'});

And in your controller:

    function productsCtrl($scope, $routeParams) {
      $scope.productId = $routeParams.productId;
    }

And in your html:

    <...productListHtml...>
    <div ng-switch="productId != null">
      <div ng-switch-when="true" ng-include="'partials/product.html'">
    </div>