Support keeping IpClient logs around and dumping them
during dumpsys. Previously we got this benefit for
wifi by virtue of WifiStateMachine's long-lived nature.
Now that this is changing we need to be sure we have
logs, and this method gets us Ethernet logs as well.
Bug: 62476366
Bug: 77999594
Test: as follows
- built
- flashed
- booted
- runtest frameworks-net passes
- dumpsys connmetrics [ipclient] works
Change-Id: I1136a83de8097fdb4130debe1eaf689be7132fe5
3f8306b8c5