Gradle error : Failed to resolve: com.google.firebase:firebase-core:16.0.1

Edit please read my question properly, as the one you say is duplicate of, didnt solve my problem!

Edit 2 please im saying it again, although the solutions to that question didnt solve my problem, why you keep saying its duplicate?!!!!

im having the same problem as this : Failed to resolve: com.google.firebase:firebase-core:16.0.1 i have done everything as in the answers! but still the problem persist!

here is my gradle project level

buildscript {

    repositories {
        google()
        jcenter()
        mavenCentral()


    }

    dependencies {


        classpath 'com.android.tools.build:gradle:3.1.3'
        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()
        mavenCentral()

    }
}

task clean(type: Delete) {
    delete rootProject.buildDir
}

and here is my gradle app level:

plugins {
    id 'com.onesignal.androidsdk.onesignal-gradle-plugin' version '0.8.0'
}

apply plugin: 'com.android.application'
apply plugin: 'com.onesignal.androidsdk.onesignal-gradle-plugin'

repositories {
    maven { url 'https://maven.google.com' }
}

android {
    compileSdkVersion 27
    defaultConfig {
        applicationId "com.example.miran3ma.wequest"
        minSdkVersion 16
        targetSdkVersion 27
        versionCode 1
        versionName "1.0"
         testInstrumentationRunner     "android.support.test.runner.AndroidJUnitRunner"
        vectorDrawables.useSupportLibrary = true

        manifestPlaceholders = [onesignal_app_id               : "my-id",
                                   dashboard, local value is ignored.
                                onesignal_google_project_number: "REMOTE"]
    }
    buildTypes {
        release {
            minifyEnabled false
            proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
        }
    }
}

dependencies {
    implementation 'com.onesignal:OneSignal:3.8.4'

    implementation('com.github.thekhaeng:pushdown-anim-click:1.0.7') {
        exclude group: 'com.android.support'
    }

    implementation 'com.squareup.picasso:picasso:2.5.2'
    implementation fileTree(include: ['*.jar'], dir: 'libs')
    implementation 'com.android.support:appcompat-v7:27.1.1'
    implementation 'com.android.support:design:27.1.1'
    implementation 'de.hdodenhof:circleimageview:2.2.0'
    implementation 'com.google.android.gms:play-services-auth:15.0.1'
    implementation 'com.android.support:support-vector-drawable:27.1.1'
    implementation 'com.android.support:support-v4:27.1.1'
    implementation 'com.android.support.constraint:constraint-layout:1.1.1'
    implementation 'com.google.firebase:firebase-database:16.0.1'
    implementation 'com.google.firebase:firebase-crash:16.0.0'
    implementation 'com.google.firebase:firebase-auth:16.0.1'
    implementation 'com.google.firebase:firebase-core:16.0.0'
    testImplementation 'junit:junit:4.12'
    implementation 'com.valdesekamdem.library:md-toast:0.9.0'
    implementation 'com.facebook.android:facebook-android-sdk:4.30.0'
    implementation 'com.google.maps.android:android-maps-utils:0.5'
    implementation 'com.google.android.gms:play-services-maps:15.0.1'
    implementation 'net.steamcrafted:load-toast:1.0.12'
    implementation 'info.hoang8f:android-segmented:1.0.6'
    implementation 'com.google.android.gms:play-services-location:15.0.1'
    implementation 'me.grantland:autofittextview:0.2.1'
    // implementation 'com.wang.avi:library:2.1.3'

    implementation 'com.google.android.gms:play-services-maps:15.0.1'
    implementation 'com.sothree.slidinguppanel:library:3.4.0'

    androidTestImplementation 'com.android.support.test:runner:1.0.1'
    androidTestImplementation 'com.android.support.test.espresso:espresso-core:3.0.1'
}

apply plugin: 'com.google.gms.google-services'

the problem only appears after updating to the latest firebase version which is 16.

any help will be appreciated, Thanks

Just for someone having the same problem, its related to OneSignal libraries importing. just read the latest onesignal documentation on adding it so the gradle and the error shall go away.