Check if Shamiko whitelist is not active before configuring DenyList

[IcyColdified]

Since creating a file named whitelist on /data/adb/shamiko/ seems to be the only way to enable whitelist mode on Shamiko, and a lot of people are complaining about this.

This PR adds a single if statement to check that whitelist mode is not enabled, before adding com.google.android.gms and com.google.android.gms.unstable to DenyList.