Google map is still blink and does not load. All the scripts, api key and code are correct.
The app gradle file is:
apply plugin: 'com.android.application'
android {
    compileSdkVersion 26
    defaultConfig {
        applicationId "com.example.muzammil.bustracking"
        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.constraint:constraint-layout:1.0.2'
    implementation 'com.google.android.gms:play-services-location:+'
    implementation 'com.google.android.gms:play-services-maps:+'
    implementation 'com.google.firebase:firebase-core:+'
    implementation 'com.google.firebase:firebase-auth:+'
    //noinspection GradleCompatible
    implementation 'com.google.firebase:firebase-messaging:+'
    testImplementation 'junit:junit:4.12'
    androidTestImplementation 'com.android.support.test:runner:1.0.1'
    androidTestImplementation 'com.android.support:design:26.1.0'
    androidTestImplementation 'com.android.support.test.espresso:espresso-core:3.0.1'
//    apply plugin: 'com.google.gms.google-services'
}
apply plugin: 'com.google.gms.google-services'
I am running app on actual Android phone , not emulator.
A lot of Thanks in advance for the answer...
 
     
     
     
    