aconfig storage daemon: add local override removal capability

Allow client to send a message to aconfigd socket to remove sticky local
override. It supports both bulk removal as well removing a single flag
local override.

Flag: enable_aconfig_storage_daemon
Bug: b/312444587
Test: atest aconfigd_test
Change-Id: I674fe85dde0d6543781bd9568f7a4ceef9921680
5 files changed