Delete the legacy experiment flag IPCLIENT_PARSE_NETLINK_EVENTS_VERSION Given we enable the feature of parsing netlink events in user space by default with a kill switch flag, then cleanup the legacy experiment flag IPCLIENT_PARSE_NETLINK_EVENTS_VERSION. Bug: 163492391 Test: atest NetworkStackTests Change-Id: I661d0981ada3032f9723bd4f348e4ee10631176c