Remove LOCKDOWN from FirewallChain IntDef

LOCKDOWN_VPN was in the FirewallChain IntDef but this was not a right
place because LOCKDOWN_VPN was not a valid value for Connectivity APIs
that take an argument annotated with @FirewallChain(setUidFirewallRule,
setFirewallChainEnabled, replaceFirewallChain).

LOCKDOWN_VPN was in the FirewallChain IntDef because
BpfNetMaps#setUidRule was used to add/remove LOCKDOWN_VPN entries.
This commit adds BpfNetMaps#updateUidLockdownRule and uses this to
add/remove LOCKDOWN_VPN entries instead of BpfNetMaps#setUidRule and
removes LOCKDOWN from FirewallChain.

Bug: 206482423
Test: atest TrafficControllerTest ConnectivityServiceTest
PermissionMonitorTest HostsideVpnTests#testBlockIncomingPacket

Change-Id: Iff9b9792fc0f208f153e10e396c6d5034b412d7c
diff --git a/service/jni/com_android_server_BpfNetMaps.cpp b/service/jni/com_android_server_BpfNetMaps.cpp
index bc70c93..2780044 100644
--- a/service/jni/com_android_server_BpfNetMaps.cpp
+++ b/service/jni/com_android_server_BpfNetMaps.cpp
@@ -151,6 +151,12 @@
     return (jint)status.code();
 }
 
+static jint native_updateUidLockdownRule(JNIEnv* env, jobject self, jint uid, jboolean add) {
+    Status status = mTc.updateUidLockdownRule(uid, add);
+    CHECK_LOG(status);
+    return (jint)status.code();
+}
+
 static jint native_swapActiveStatsMap(JNIEnv* env, jobject self) {
     Status status = mTc.swapActiveStatsMap();
     CHECK_LOG(status);
@@ -203,6 +209,8 @@
     (void*)native_addUidInterfaceRules},
     {"native_removeUidInterfaceRules", "([I)I",
     (void*)native_removeUidInterfaceRules},
+    {"native_updateUidLockdownRule", "(IZ)I",
+    (void*)native_updateUidLockdownRule},
     {"native_swapActiveStatsMap", "()I",
     (void*)native_swapActiveStatsMap},
     {"native_setPermissionForUids", "(I[I)V",