BpfNetMaps.java - array index U32 -> S32

This converts the key, which is an index in an array, of sConfigurationMap from U32 to S32.

Since the array has exactly 2 elements, there's no real difference.
In addition while the kernel does indeed index arrays with U32s,
it doesn't matter, because you'd need to have over 2 billion
elements in the bpf map (at which point you'd need GBs of ram for
the bpf map itself)...

Test: TreeHugger
Signed-off-by: Maciej Żenczykowski <maze@google.com>
Change-Id: If17efc25d910af642e519f9ecb6d0e8695c38d42

tests/unit/java/com/android/server/BpfNetMapsTest.java

@@ -103,8 +103,8 @@ public final class BpfNetMapsTest {
     private static final int NO_IIF = 0;
     private static final int NULL_IIF = 0;
     private static final String CHAINNAME = "fw_dozable";
-    private static final U32 UID_RULES_CONFIGURATION_KEY = new U32(0);
-    private static final U32 CURRENT_STATS_MAP_CONFIGURATION_KEY = new U32(1);
+    private static final S32 UID_RULES_CONFIGURATION_KEY = new S32(0);
+    private static final S32 CURRENT_STATS_MAP_CONFIGURATION_KEY = new S32(1);
     private static final List<Integer> FIREWALL_CHAINS = List.of(
             FIREWALL_CHAIN_DOZABLE,
             FIREWALL_CHAIN_STANDBY,
@@ -124,7 +124,7 @@ public final class BpfNetMapsTest {
     @Mock INetd mNetd;
     @Mock BpfNetMaps.Dependencies mDeps;
     @Mock Context mContext;
-    private final IBpfMap<U32, U32> mConfigurationMap = new TestBpfMap<>(U32.class, U32.class);
+    private final IBpfMap<S32, U32> mConfigurationMap = new TestBpfMap<>(S32.class, U32.class);
     private final IBpfMap<S32, UidOwnerValue> mUidOwnerMap =
             new TestBpfMap<>(S32.class, UidOwnerValue.class);
     private final IBpfMap<S32, U8> mUidPermissionMap = new TestBpfMap<>(S32.class, U8.class);