PlatformException (PlatformException(sign_in_failed, com.google.android.gms.common.api.ApiException: 10: , null)) - Google sign in returning exception

Upon attempting to connect google sign in through firebase with my flutter application I run into this error:

PlatformException (PlatformException(sign_in_failed, com.google.android.gms.common.api.ApiException: 10: , null))

I have done all of the listed below:

1. Generated the SHA1 key several times using this command:

   keytool -list -v \ > -alias androiddebugkey -keystore ~/.android/debug.keystore

2. Added implementation "com.google.firebase:firebase-core:16.0.9" inside of the dependencies into android/app/build.gradle as well apply plugin: 'com.google.gms.google-services' at the bottom of the .gradle file

3. Added both of the following lines inside of dependencies in android/build.gradle:

   classpath 'com.android.tools.build:gradle:3.5.0'

   classpath 'com.google.gms:google-services:4.2.0'

4. Connected a support email inside of firebase

5. Enabled google sign in method inside of firebase

6. Deleted and re-installed the google-services.json file which I placed inside of android/app/ as well as the GoogleService-Info.plist which I placed in ios/Runner

7. Added the latest version of google_sign_in from pub.dev (google_sign_in: ^4.5.1) located in pubspec.yaml

8. Checked out all other posts of people experiencing a similar issue (StackOverflow and GitHub) and attempted to do what worked for them but so far nothing has worked for me