Map status dump will do access check if map is null.
This could show different message from the current dump output.
Information in map content dump does not change
$ dumpsys connectivity trafficcontroller
....
mIfaceIndexNameMap:
ifaceIndex=5 ifaceName=ip6_vti0
ifaceIndex=19 ifaceName=r_rmnet_data3
ifaceIndex=17 ifaceName=r_rmnet_data1
ifaceIndex=18 ifaceName=r_rmnet_data2
ifaceIndex=23 ifaceName=wifi-aware0
....
$ dumpsys netstats
....
BPF map content:
ifaceIndex=5 ifaceName=ip6_vti0
ifaceIndex=19 ifaceName=r_rmnet_data3
ifaceIndex=17 ifaceName=r_rmnet_data1
ifaceIndex=18 ifaceName=r_rmnet_data2
ifaceIndex=8 ifaceName=rmnet_ipa0
....
Bug: 217624062
Test: dumpsys netstats, atest
com.android.server.net.BpfInterfaceMapUpdaterTest
Change-Id: If182bd97f72713b6347028668cf7bd4676b8aea4