Revert "ClatCoordinator - use SingleWriterBpfMap"

This reverts commit I93b8b94dcad8f2bc4d022314372fb97109ed8f2f.

Reason for revert: ClatIngress6Value and ClatEgress4Value are written to by the clatd.c program (reference aosp/3002596). Due to this, SingleWriterBpfMap is unsuitable in this scenario, as it can only be used when no BPF program ever writes to the map.

Change-Id: I382bbfc8554391c6c83a39bbea155114202b71a8
diff --git a/service/src/com/android/server/connectivity/ClatCoordinator.java b/service/src/com/android/server/connectivity/ClatCoordinator.java
index b1c770b..f333dae 100644
--- a/service/src/com/android/server/connectivity/ClatCoordinator.java
+++ b/service/src/com/android/server/connectivity/ClatCoordinator.java
@@ -45,7 +45,6 @@
 import com.android.net.module.util.BpfMap;
 import com.android.net.module.util.IBpfMap;
 import com.android.net.module.util.InterfaceParams;
-import com.android.net.module.util.SingleWriterBpfMap;
 import com.android.net.module.util.TcUtils;
 import com.android.net.module.util.bpf.ClatEgress4Key;
 import com.android.net.module.util.bpf.ClatEgress4Value;
@@ -257,7 +256,7 @@
         @Nullable
         public IBpfMap<ClatIngress6Key, ClatIngress6Value> getBpfIngress6Map() {
             try {
-                return SingleWriterBpfMap.getSingleton(CLAT_INGRESS6_MAP_PATH,
+                return new BpfMap<>(CLAT_INGRESS6_MAP_PATH,
                        ClatIngress6Key.class, ClatIngress6Value.class);
             } catch (ErrnoException e) {
                 Log.e(TAG, "Cannot create ingress6 map: " + e);
@@ -269,7 +268,7 @@
         @Nullable
         public IBpfMap<ClatEgress4Key, ClatEgress4Value> getBpfEgress4Map() {
             try {
-                return SingleWriterBpfMap.getSingleton(CLAT_EGRESS4_MAP_PATH,
+                return new BpfMap<>(CLAT_EGRESS4_MAP_PATH,
                        ClatEgress4Key.class, ClatEgress4Value.class);
             } catch (ErrnoException e) {
                 Log.e(TAG, "Cannot create egress4 map: " + e);
@@ -281,7 +280,6 @@
         @Nullable
         public IBpfMap<CookieTagMapKey, CookieTagMapValue> getBpfCookieTagMap() {
             try {
-                // also read and written from other locations
                 return new BpfMap<>(COOKIE_TAG_MAP_PATH,
                        CookieTagMapKey.class, CookieTagMapValue.class);
             } catch (ErrnoException e) {