Android Studio – Could not resolve com.google.android.gms:play-services-measurement-base:[18.0.0]

I am relatively new to Flutter and the project was working 2 days ago.
When I tried to run it today, and I met with this error.
This is the error I’m facing.

FAILURE: Build failed with an exception.

* What went wrong:
Could not determine the dependencies of task ':app:processDebugResources'.
> Could not resolve all task dependencies for configuration ':app:debugRuntimeClasspath'.
   > Could not resolve com.google.android.gms:play-services-measurement-base:[18.0.0].
     Required by:
         project :app > com.google.firebase:firebase-analytics:18.0.0 > com.google.android.gms:play-services-measurement:18.0.0
         project :app > com.google.firebase:firebase-analytics:18.0.0 > com.google.android.gms:play-services-measurement-api:18.0.0
         project :app > com.google.firebase:firebase-analytics:18.0.0 > com.google.android.gms:play-services-measurement-sdk:18.0.0
         project :app > com.google.firebase:firebase-analytics:18.0.0 > com.google.android.gms:play-services-measurement:18.0.0 > com.google.android.gms:play-services-measurement-impl:18.0.0
         project :app > com.google.firebase:firebase-analytics:18.0.0 > com.google.android.gms:play-services-measurement-api:18.0.0 > com.google.android.gms:play-services-measurement-sdk-api:18.0.0
      > Failed to list versions for com.google.android.gms:play-services-measurement-base.
         > Unable to load Maven meta-data from https://google.bintray.com/exoplayer/com/google/android/gms/play-services-measurement-base/maven-metadata.xml.
            > Could not get resource 'https://google.bintray.com/exoplayer/com/google/android/gms/play-services-measurement-base/maven-metadata.xml'.
               > Could not GET 'https://google.bintray.com/exoplayer/com/google/android/gms/play-services-measurement-base/maven-metadata.xml'. Received status code 502 from server: Bad Gateway

This is the code for my appbuild.gradle

def localProperties = new Properties()
def localPropertiesFile = rootProject.file('local.properties')
if (localPropertiesFile.exists()) {
    localPropertiesFile.withReader('UTF-8') { reader ->
        localProperties.load(reader)
    }
}

def flutterRoot = localProperties.getProperty('flutter.sdk')
if (flutterRoot == null) {
    throw new GradleException("Flutter SDK not found. Define location with flutter.sdk in the local.properties file.")
}

def flutterVersionCode = localProperties.getProperty('flutter.versionCode')
if (flutterVersionCode == null) {
    flutterVersionCode = '1'
}

def flutterVersionName = localProperties.getProperty('flutter.versionName')
if (flutterVersionName == null) {
    flutterVersionName = '1.0'
}

apply plugin: 'com.android.application'
apply plugin: 'kotlin-android'
apply plugin: 'com.google.gms.google-services'
apply from: "$flutterRoot/packages/flutter_tools/gradle/flutter.gradle"

android {
    compileSdkVersion 29

    sourceSets {
        main.java.srcDirs += 'src/main/kotlin'
    }

    lintOptions {
        disable 'InvalidPackage'
    }

    defaultConfig {
        applicationId "com.project.project"
        minSdkVersion 21
        targetSdkVersion 29
        versionCode flutterVersionCode.toInteger()
        versionName flutterVersionName
        multiDexEnabled true
    }

    buildTypes {
        release {
            signingConfig signingConfigs.debug
        }
    }
}

flutter {
    source '../..'
}

dependencies {
    implementation "org.jetbrains.kotlin:kotlin-stdlib-jdk7:$kotlin_version"
    implementation platform('com.google.firebase:firebase-bom:26.1.1')
    implementation 'com.google.firebase:firebase-analytics'
    implementation 'com.android.support:multidex:1.0.3'
}

I tried updating firebase-bom and google-services but was still facing the same problem.
Any help would be greatly appreciated!