How to rename android package name using gradle to cmd?

Question

How to rename android package name using gradle to cmd?

I want to rename the package name using gradle to cmd.because I have multiple project settings and changing the package name using ide is very difficult to change the name of each package separately. Please give me a solution.thanks in advance

 apply plugin: 'com.android.application'
    apply plugin: 'maven'

    android {
        compileSdkVersion 21
        buildToolsVersion "23.0.0 rc2"


        sourceSets {
            defaultConfig {
                applicationId "com.appbell.restaurant.genericresto"
                minSdkVersion 14
                targetSdkVersion 19
                compileOptions {
                    sourceCompatibility JavaVersion.VERSION_1_7
                    targetCompatibility JavaVersion.VERSION_1_7
                }

            }
            main {
                manifest.srcFile 'src\\main\\AndroidManifest.xml'
                println('android'+manifest.srcFile)
            }

        }

        buildTypes {
            release {
                minifyEnabled true
                proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.txt'
            }
        }
    }

    task changePackage{
        replaceInManifest("com.appbell.restaurant.example","com.appbell.imenu4u")
    }

    buildscript {
        repositories {
            mavenCentral()
        }
        dependencies {
            // Make sure this is at least 0.10.+
            classpath 'com.android.tools.build:gradle:1.0.+'
        }
    }

    task appStart(type: Exec, dependsOn: 'installDebug') {
        // linux
        //commandLine 'adb', 'shell', 'am', 'start', '-n', 'com.example/.MyActivity'
        // windows
         commandLine 'cmd', '/c', 'adb', 'shell', 'am', 'start', '-n', 'com.appbell.restaurant.genericresto/com.appbell.and.resto.and.ui.SplashActivity'
    }

    dependencies {
        compile project(':facebook')
        compile project(':stripe')
        compile 'com.google.android.gms:play-services:+'
        compile 'com.android.support:appcompat-v7:21.0.3'
        compile files('libs/mobileappclasses.jar')
        compile files('libs/pgsdk.jar')
    }

    def replaceInManifest(fromString, toString) {
        def manifestFile = "C:\\Users\\Ntin Gorle\\AndroidstudioProjects\\MyApplication\\RestoAppNEw\\src\\main\\AndroidManifest.xml"
        def updatedContent = new File(manifestFile).getText('UTF-8').replaceAll(fromString, toString)
        new File(manifestFile).write(updatedContent, 'UTF-8')
    }