Cannot Connect to Firebase From Android Studio using Firebase Assistant - firebase

Question

I do have problem in connecting to Firebase from Android Studio using Firebase Assistant. It just popup this image when i try to connect to Firebase. I'm quite new to Firebase and Android Development so this is a little problem to me.
This is my build.gradle for project
// Top-level build file where you can add configuration options common to all sub-projects/modules.
buildscript {
repositories {
google()
jcenter()
}
dependencies {
classpath 'com
.android.tools.build:gradle:3.2.1'
classpath 'com.google.gms:google-
services:4.0.1'
// NOTE: Do not place your application
dependencies here; they belong
// in the individual module build.gradle files
}
}
allprojects {
repositories {
google()
jcenter()
}
}
task clean(type: Delete) {
delete rootProject.buildDir
}
And this is my build.gradle (App)
apply plugin: 'com.android.application'
android {
compileSdkVersion 28
defaultConfig {
applicationId "com.thebooksmart.booksmart"
minSdkVersion 23
targetSdkVersion 28
versionCode 1
versionName "1.0"
testInstrumentationRunner
"android.support.test.runner.AndroidJUnitRunner"
}
buildTypes {
release {
minifyEnabled false
proguardFiles
getDefaultProguardFile('proguard-
android.txt'), 'proguard-rules.pro'
}
}
}
dependencies {
implementation fileTree(dir: 'libs',include: ['*.jar'])
implementation 'com.android.support:appcompat-v7:28.0.0'
implementation 'com.android.support.constraint:constraint-layout:1.1.3'
testImplementation 'junit:junit:4.12'
androidTestImplementation 'com.android.support.test:runner:1.0.2'
androidTestImplementation 'com.android.support.test.espresso:espresso-core:3.0.2'
implementation 'com.android.support:design:28.0.0'
implementation 'com.android.support:support-v4:28.0.0'
implementation 'com.android.support:gridlayout-v7:28.0.0'
implementation 'com.google.firebase:firebase-core:16.0.1'
}
apply plugin: 'com.google.gms.google-services'
Requesting help from experts or anyone that know how to sort this