liblog: Support for ANDROID_LOG_WRAP mode flag on reader

If ANDROID_LOG_WRAP is specified, add timeout=3600 to the reader
request. logd will comply by going to sleep with the socket open.
If the start time is about to wrap or get pruned in the specified log
buffers, then wakeup and dump the logs; or wakeup on timeout,
whichever comes first.

Bug: 25929746
Change-Id: I531b4317a20abcf3ba87d78c68fa2f268a4488ab