If no module name is provided, then try to load modules based on the
device modealias.
Previously, MODALIAS property is passed as an argument, but it may
contain quotation. Hence, unfortunately the modalias may be modified
and cannot load expected modules.
Fixes#24715.
Add quotes around use of $env{MODALIAS} in rules.d/80-drivers.rules. The
modalias can contain whitespace, for example when it is dynamically generated
using device or vendor IDs.
This change is only about the source tree. We have tmpfiles.d/, modprobe.d/,
sysctl.d/, and sysusers.d/, but for historical reasons, rules/ didn't fit this
pattern. We also *install* it as rules.d/. Let's rename to be consistent.