Android JUnit 4 Missing

Error

C:\Users\Chris\IdeaProjects\MyApplication3\app\src\androidTest\java\com\example\myapplication\ExampleInstrumentedTest.java:5: error: package androidx.test.ext.junit.runners does not exist
import androidx.test.ext.junit.runners.AndroidJUnit4;

opening the java class you can see the the import does not exist:

import androidx.test.ext.junit.runners.AndroidJUnit4;

To fix the issue open app/build.grade and include the line:

androidTestImplementation ‘androidx.test.ext:junit:1.1.1’

apply plugin: 'com.android.application'

android {
    compileSdkVersion 28
    defaultConfig {
        applicationId "com.example.myapplication"
        minSdkVersion 19
        targetSdkVersion 28
        versionCode 1
        versionName "1.0"
        testInstrumentationRunner "androidx.test.runner.AndroidJUnitRunner"
    }
    buildTypes {
        release {
            minifyEnabled false
            proguardFiles getDefaultProguardFile('proguard-android-optimize.txt'), 'proguard-rules.pro'
        }
    }
}

dependencies {
    implementation fileTree(dir: 'libs', include: ['*.jar'])
    implementation 'androidx.appcompat:appcompat:1.0.2'
    implementation 'com.google.android.material:material:1.0.0'
    implementation 'androidx.constraintlayout:constraintlayout:1.1.3'
    implementation 'androidx.navigation:navigation-fragment:2.0.0'
    implementation 'androidx.navigation:navigation-ui:2.0.0'
    implementation 'androidx.lifecycle:lifecycle-extensions:2.0.0'
    testImplementation 'junit:junit:4.12'
    androidTestImplementation 'androidx.test:runner:1.1.1'
    androidTestImplementation 'androidx.test.espresso:espresso-core:3.1.1'
    androidTestImplementation 'androidx.test.ext:junit:1.1.1'
}