DO NOT MERGE: IpConnectivityMetrics reads buffer size in settings

Test: IpConnectivityMetricsTest passes. Also manually changed the new
setting and verified the buffer size is as expected after flushing the
buffer.
Bug: 32198637

(cherry picked from commit 05686dbb6b965eb1a54591d2ed2334337886c6ee)

Change-Id: Iefbeac3a688b260fb3f92dfe0bfd9db28e26749d
3 files changed