Disable KeepaliveStatsTracker instead of throwing.

Avoid throwing errors when something unexpected occurs with the
keepalive state since metrics should not cause a crash. Instead, disable
the tracker and skip writing the metrics.

Bug: 288059409
Test: atest FrameworksNetTests
Change-Id: I1cd5acb32eb062ccdf7d1ac3e25a21309ad011c2
3 files changed