Count and Report Bandwidth Requests by UID

To debug power drain due to modem wakeups,
one of the signals we'd like to track is
requests for bandwidth estimate to see which
apps are making requests and how often. This
patch keeps a simple count per-UID when an
app requests a bandwidth update, and that
count is made available in dumpsys.

Bug: 77498849
Test: runtest frameworks-net
Change-Id: I30d2ce85f9fa6747030cf4039d1080113a32e386