Reduce timeout for DUMP NETSTATS PROTO

This change reduces the timeout on 'dumpsys netstats --proto' from 120s
to 5s. This is because go/bugreport-durations shows that the DUMP
NETSTATS PROTO is always under 1s unless it stalls, in which case it
will always hit the timeout.

Ignore-AOSP-First: The netstats section only exists on internal builds.
Test: Collect a bug report with 'adb bugreportz' to verify that the
      'DUMP NETSTATS PROTO' section still exists.
Bug: 249522178
Change-Id: I377bdb0ea61b53e76b6329fc52d634d1c2c0b0ad