Gradle sync failed: Could not resolve all dependencies for configuration ':app:debugRuntimeClasspath'

Question

I recently update my Android Studio to version 3.0.1 and I started a new project with a blank activity. As soon as the gradle sync starts(as soon as I open the project)I get a message in Event Log :

Gradle sync failed: Could not resolve all dependencies for configuration ':app:debugRuntimeClasspath'.
                Could not determine artifacts for com.android.support:appcompat-v7:26.1.0
                Could not get resource 'https://dl.google.com/dl/android/maven2/com/android/support/appcompat-v7/26.1.0/appcompat-v7-26.1.0.aar'.
                Could not HEAD 'https://dl.google.com/dl/android/maven2/com/android/support/appcompat-v7/26.1.0/appcompat-v7-26.1.0.aar'.
                Connect to dl.google.com:443 [dl.google.com/216.58.197.46] failed: Connection refused: connect
                Connection refused: connect
                Consult IDE log for more details (Help | Show Log) (3s 878ms)

I reinstalled the support repository from Android SDK manager and adding maven to the dependencies but so far have been unable to resolve the issue.

The build-gradle:

// 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:3.0.1'

    // NOTE: Do not place your application dependencies here; they belong
    // in the individual module build.gradle files
 }
}

allprojects {
 repositories {
    google()
    jcenter()
    maven { url "https://maven.google.com" }
    }
}

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

app level build-gradle:

apply plugin: 'com.android.application'

android {
 compileSdkVersion 26
 defaultConfig {
    applicationId "com.example.vishalbisht.test"
    minSdkVersion 15
    targetSdkVersion 26
    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-v7:26.1.0'
 implementation 'com.android.support:design:26.1.0'
 implementation 'com.android.support.constraint:constraint-layout:1.0.2'
 testImplementation 'junit:junit:4.12'
 androidTestImplementation 'com.android.support.test:runner:1.0.1'
 androidTestImplementation 'com.android.support.test.espresso:espresso-
 core:3.0.1'
}

Answer 1

I was able to get around this issue by commenting the following lines in app level build-gradle

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

and then it started working not sure if this is an acceptable solution but as of know I can at least run and compile my code.

Also after the Android studio 3.1 update, I have not faced this issue.