BpfNetworkStats - remove spurious code & use static maps

frameworks/libs/net/common/native/bpf_headers/include/bpf/BpfMap.h
(which is a mainline automerged path)

already aborts() on failure in the path taking constructor
(by calling abortOnKeyOrValueSizeMismatch), and as such
checking for isValid afterwards is pointless.

Also, there's no reason to waste cpu cycles opening and closing these maps, and creating and destroying the map objects.

Test: TreeHugger
Signed-off-by: Maciej Żenczykowski <maze@google.com>
Change-Id: Icb5567ee32ca9a00fd8aeb565066716d350f1292
1 file changed