If you don’t care about it being a Nexus 6P, you can run
echo no | Android/Sdk/tools/bin/avdmanager create avd --force --name testAVD --abi google_apis/x86_64 --package 'system-images;android-23;google_apis;x86_64'
If you don’t care about it being a Nexus 6P, you can run
echo no | Android/Sdk/tools/bin/avdmanager create avd --force --name testAVD --abi google_apis/x86_64 --package 'system-images;android-23;google_apis;x86_64'