Start aconfigd socket defined in configinfra mainline module

Context: to have better future updatability. The responsiblity of
managing mainline module storage files and a socket service for flag
overrides will be moved to the configinfra mainline module. Later,
aconfigd on /system will only be repsopnsbile for managing platform
partition storage files.

Bug: b/369810972
Test: m, launch avd and then inspect the logcat log to confirm the
service is launched.

Change-Id: I490e5aa432fa4afa236689ad0999e5602f7d297e