Add variable to aid errorprone update

// subdirs= and optional_subdirs= are obsolete and this file no longer

// needs a list of the top level directories that may contain Android.bp

// files.

// TODO(b/253827323) Remove this. A module in internal builds needs to disable a new check,

// IdentifierName, when errorprone is updated. In order to avoid having the update errorprone

// in internal first, and then aosp, create this variable that we can fill out in internal in the

// same topic as the errorprone update, then move the flag out of the variable after the update,

// then remove the variable.

disable_identifiername_for_errorprone_update = []