Migrate MAC Addresses and BSSIDs from std::vector to std::array

Since MAC Addresses and BSSIDs are fixed size, it would be more
efficient to use a fixed length array to store them. Also, bugs
causing MAC Addresses to have the wrong size can be caught
more promptly than before.

Bug: 36974160
Fix: 36974160
Test: system/connectivity/wificond/runtests.sh
Test: manual - flash onto device and try connecting to Wifi
Change-Id: Iefab0b3bbfd286c135b10ccc4fa946faaad86ce4
diff --git a/logging_utils.cpp b/logging_utils.cpp
index f717a50..189f0dd 100644
--- a/logging_utils.cpp
+++ b/logging_utils.cpp
@@ -16,19 +16,19 @@
 
 #include "wificond/logging_utils.h"
 
+#include <array>
 #include <iomanip>
-#include <vector>
 
 #include <android-base/macros.h>
 
+using std::array;
 using std::string;
 using std::stringstream;
-using std::vector;
 
 namespace android {
 namespace wificond {
 
-string LoggingUtils::GetMacString(const vector<uint8_t>& mac_address) {
+string LoggingUtils::GetMacString(const array<uint8_t, ETH_ALEN>& mac_address) {
   stringstream ss;
   for (const uint8_t& b : mac_address) {
     ss << std::hex << std::setfill('0') << std::setw(2) << static_cast<int>(b);