Remove the deleted stats from map

The xt_qtaguid module removes per uid stats when an app get uninstalled.
So eBPF map should not store the uninstalled stats either. This change
help fix the unknown iface problem as well.

Bug: 77987430
Test: android.app.usage.cts.NetworkUsageStatsTest
Change-Id: Ieb08833ecc35f76d27769042f197d889470faf7f
Merged-In: Ieb08833ecc35f76d27769042f197d889470faf7f
(cherry picked from aosp commit ef1cab3a)