@Sujan12, @fdom and @reedrichards Please have a llok below screenshots.
I clone a fresh ionic repo using ionic start super --type=ionic-angular command.
It’s run successfully in my system and i also try to build release apk. It’s Strange it takes > 30 sec to boot app. 
when i check inside network tabs i found something: please check vendor.js and load time also:
Here is my package.json (provided by ionic):
{
"name": "tabs",
"version": "0.0.1",
"author": "Ionic Framework",
"homepage": "http://ionicframework.com/",
"private": true,
"scripts": {
"clean": "ionic-app-scripts clean",
"build": "ionic-app-scripts build",
"lint": "ionic-app-scripts lint",
"ionic:build": "ionic-app-scripts build",
"ionic:serve": "ionic-app-scripts serve"
},
"dependencies": {
"@angular/common": "4.1.3",
"@angular/compiler": "4.1.3",
"@angular/compiler-cli": "4.1.3",
"@angular/core": "4.1.3",
"@angular/forms": "4.1.3",
"@angular/http": "4.1.3",
"@angular/platform-browser": "4.1.3",
"@angular/platform-browser-dynamic": "4.1.3",
"@ionic-native/camera": "3.12.1",
"@ionic-native/core": "3.12.1",
"@ionic-native/google-maps": "3.12.1",
"@ionic-native/splash-screen": "3.12.1",
"@ionic-native/status-bar": "3.12.1",
"@ionic/storage": "2.0.1",
"@ngx-translate/core": "6.0.1",
"@ngx-translate/http-loader": "0.0.3",
"cordova-android": "^6.2.3",
"cordova-plugin-console": "^1.0.5",
"cordova-plugin-device": "^1.1.4",
"cordova-plugin-splashscreen": "^4.0.3",
"cordova-plugin-statusbar": "^2.2.2",
"cordova-plugin-whitelist": "^1.3.1",
"ionic-angular": "3.5.3",
"ionic-plugin-keyboard": "^2.2.1",
"ionicons": "3.0.0",
"rxjs": "5.4.0",
"sw-toolbox": "3.6.0",
"zone.js": "0.8.12"
},
"devDependencies": {
"@ionic/app-scripts": "2.0.2",
"@ionic/cli-plugin-cordova": "1.4.1",
"@ionic/cli-plugin-ionic-angular": "1.3.2",
"typescript": "2.3.4"
},
"description": "An Ionic project",
"cordova": {
"plugins": {
"cordova-plugin-console": {},
"cordova-plugin-device": {},
"cordova-plugin-splashscreen": {},
"cordova-plugin-statusbar": {},
"cordova-plugin-whitelist": {},
"ionic-plugin-keyboard": {}
},
"platforms": [
"android"
]
}
}
In short i haven’t change anything that is provided by ionic team although, why it takes too much time ?