Getting could not resolve all artifact error at application run - android-studio

Question

Recently after upgrading android studio 4.1 my app started to stuck in "running gradle task assembledebug" so i checked the web for possible solution
Tried flutter clean and gradle commands changed gradle files but nothing worked finally deleted gradle and reinstalled android studio again but now i can't get android sdk 28 to be installed (it doesnt appear in sdk list) so i changed sdk to 29 but whenever i try to run my app it gives the fallowing errors
FAILURE: Build failed with an exception.
* What went wrong:
A problem occurred configuring root project 'android'.
> Could not resolve all artifacts for configuration ':classpath'.
> Could not resolve com.android.tools.build:gradle:3.5.3.
Required by:
project :
> Could not resolve com.android.tools.build:gradle:3.5.3.
> Could not get resource 'https://dl.google.com/dl/android/maven2/com/android/tools/build/gradle/3.5.3/gradle-3.5.3.pom'.
> Could not GET 'https://dl.google.com/dl/android/maven2/com/android/tools/build/gradle/3.5.3/gradle-3.5.3.pom'.
> Connect to localhost:3128 [localhost/127.0.0.1, localhost/0:0:0:0:0:0:0:1] failed: Connection refused: connect
> Could not resolve com.android.tools.build:gradle:3.5.3.
> Could not get resource 'https://jcenter.bintray.com/com/android/tools/build/gradle/3.5.3/gradle-3.5.3.pom'.
> Could not GET 'https://jcenter.bintray.com/com/android/tools/build/gradle/3.5.3/gradle-3.5.3.pom'.
> Connect to localhost:3128 [localhost/127.0.0.1, localhost/0:0:0:0:0:0:0:1] failed: Connection refused: connect
> Could not resolve com.google.gms:google-services:4.3.4.
Required by:
project :
> Could not resolve com.google.gms:google-services:4.3.4.
> Could not get resource 'https://dl.google.com/dl/android/maven2/com/google/gms/google-services/4.3.4/google-services-4.3.4.pom'.
> Could not GET 'https://dl.google.com/dl/android/maven2/com/google/gms/google-services/4.3.4/google-services-4.3.4.pom'.
> Connect to localhost:3128 [localhost/127.0.0.1, localhost/0:0:0:0:0:0:0:1] failed: Connection refused: connect
> Could not resolve com.google.gms:google-services:4.3.4.
> Could not get resource 'https://jcenter.bintray.com/com/google/gms/google-services/4.3.4/google-services-4.3.4.pom'.
> Could not GET 'https://jcenter.bintray.com/com/google/gms/google-services/4.3.4/google-services-4.3.4.pom'.
> Connect to localhost:3128 [localhost/127.0.0.1, localhost/0:0:0:0:0:0:0:1] failed: Connection refused: connect
* Try:
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* Get more help at https://help.gradle.org
BU�LD FAILED in 1m 24s
Exception: Gradle task assembleDebug failed with exit code 1
My current project level build gradle file is like this.
buildscript {
repositories {
google()
jcenter()
}
dependencies {
classpath 'com.android.tools.build:gradle:3.5.3'
classpath 'com.google.gms:google-services:4.3.4'
}
}
allprojects {
repositories {
google()
jcenter()
}
}
rootProject.buildDir = '../build'
subprojects {
project.buildDir = "${rootProject.buildDir}/${project.name}"
}
subprojects {
project.evaluationDependsOn(':app')
}
task clean(type: Delete) {
delete rootProject.buildDir
}
App lvl build gradle file is like this:
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 from: "$flutterRoot/packages/flutter_tools/gradle/flutter.gradle"
android {
compileSdkVersion 29
lintOptions {
disable 'InvalidPackage'
}
defaultConfig {
// TODO: Specify your own unique Application ID (https://developer.android.com/studio/build/application-id.html).
applicationId "com.farukdurusoy.sayi_avi"
minSdkVersion 16
targetSdkVersion 29
versionCode flutterVersionCode.toInteger()
versionName flutterVersionName
testInstrumentationRunner "androidx.test.runner.AndroidJUnitRunner"
multiDexEnabled true
}
buildTypes {
release {
// TODO: Add your own signing config for the release build.
// Signing with the debug keys for now, so `flutter run --release` works.
signingConfig signingConfigs.debug
}
}
}
flutter {
source '../..'
}
dependencies {
testImplementation 'junit:junit:4.12'
androidTestImplementation 'androidx.test:runner:1.1.1'
androidTestImplementation 'androidx.test.espresso:espresso-core:3.1.1'
}
apply plugin: 'com.google.gms.google-services'
Also disabled my firewalls. Any suggestions?