lineage-sdk: Add LineageGlobalActions service

The service will offer updateUserConfig, getUserConfig, and
userConfigContains methods, which will be used from LineageParts and
fwb. The service will also observe Settings.Global.BUGREPORT_IN_POWER_MENU
and Settings.Secure.LOCKDOWN_IN_POWER_MENU to update the GlobalActions
dialog when these are updated.

Signed-off-by: Gegham Zakaryan <zakaryan.2004@outlook.com>
Change-Id: I46663ab1ffe6f8d8b2a3dc7dbe54a65b7a62046a