Increase SO_RCVBUF used in IpClientLinkObserver to 4MB and ignore ENOBUFS. am: 148f574281 am: 2027d4a8b0

Original change: https://googleplex-android-review.googlesource.com/c/platform/packages/modules/NetworkStack/+/18816727

Change-Id: I14529e1f3ebbabd865b52320e3790da6fe9debdb
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>