apf: Add counters for dropped / passed packets

ApfFilter maintains separate counters for each reason why a packet was
passed or dropped by the filter logic.

There's also a total which should match the individual counters,
*unless* the APF interpreter aborted execution early due to an illegal
instruction or an out-of-bounds access.

Test: both on APFv2 and APFv4-capable device:
	runtest -x tests/net/java/android/net/ip/IpClientTest.java
	runtest -x tests/net/java/android/net/apf/ApfTest.java
	manual tests connected to an AP
Bug: 73804303
Change-Id: I54b17fcbb95dfaea5db975d282314ce73d79d6ec

services/net/java/android/net/apf/ApfCapabilities.java

@@ -49,4 +49,14 @@ public class ApfCapabilities {
         return String.format("%s{version: %d, maxSize: %d, format: %d}", getClass().getSimpleName(),
                 apfVersionSupported, maximumApfProgramSize, apfPacketFormat);
     }
+
+    /**
+     * Returns true if the APF interpreter advertises support for the data buffer access opcodes
+     * LDDW and STDW.
+     *
+     * Full LDDW and STDW support is present from APFv4 on.
+     */
+    public boolean hasDataAccess() {
+        return apfVersionSupported >= 4;
+    }
 }