Errors when building the file with admobs and play gameservice plugin

Hi

I have recently completed my 2D game project in Unity and Im trying to publish on playstore.However Im facing various errors when building the apk file after importing the google ads plugin and play game service plug in. With SDK build tools, it was shown that unable to convert classes in to hex format I downgraded the build tool to lower versions,then the error became " Failed to repack resources

Please help me

Google mobile ads Plugin v3.15.0 from https://github.com/googleads/googleads-mobile-unity/releases

Google play service plug in from https://github.com/playgameservices/play-games-plugin-for-unity

Android SDK build tools vesrion 28.0.2 Android SDK platform 28