ApfCounterTracker - reserve three slots for APFv6 endianness and allocate/transmit failure

Technically only needed for APFv6+, but easier to always reserve.

See also: aosp/2930730

Test: TreeHugger
Signed-off-by: Maciej Żenczykowski <maze@google.com>
Change-Id: I32515c9d3b9126f1b1e74d3f64d97facf3e8bdcf

src/android/net/apf/ApfCounterTracker.java

diff --git a/src/android/net/apf/ApfCounterTracker.java b/src/android/net/apf/ApfCounterTracker.java
index 0527666..b02efa0 100644
--- a/src/android/net/apf/ApfCounterTracker.java
+++ b/src/android/net/apf/ApfCounterTracker.java
@@ -40,7 +40,10 @@
     @VisibleForTesting
     public enum Counter {
         RESERVED_OOB,  // Points to offset 0 from the end of the buffer (out-of-bounds)
-        TOTAL_PACKETS,
+        ENDIANNESS,              // APFv6 interpreter stores 0x12345678 here
+        TOTAL_PACKETS,           // hardcoded in APFv6 interpreter
+        PASSED_ALLOCATE_FAILURE, // hardcoded in APFv6 interpreter
+        PASSED_TRANSMIT_FAILURE, // hardcoded in APFv6 interpreter
         PASSED_ARP,
         PASSED_DHCP,
         PASSED_IPV4,