Save last-known server time offset.

libsignal/service/src/main/java/org/whispersystems/signalservice/api/RemoteConfigResult.kt

@@ -0,0 +1,11 @@
+/*
+ * Copyright 2023 Signal Messenger, LLC
+ * SPDX-License-Identifier: AGPL-3.0-only
+ */
+
+package org.whispersystems.signalservice.api
+
+data class RemoteConfigResult(
+  val config: Map<String, Any>,
+  val serverEpochTimeSeconds: Long
+)

libsignal/service/src/main/java/org/whispersystems/signalservice/api/SignalServiceAccountManager.java

@@ -626,7 +626,7 @@ public class SignalServiceAccountManager {
     }
   }
 
-  public Map<String, Object> getRemoteConfig() throws IOException {
+  public RemoteConfigResult getRemoteConfig() throws IOException {
     RemoteConfigResponse response = this.pushServiceSocket.getRemoteConfig();
     Map<String, Object>  out      = new HashMap<>();
 
@@ -634,7 +634,7 @@ public class SignalServiceAccountManager {
       out.put(config.getName(), config.getValue() != null ? config.getValue() : config.isEnabled());
     }
 
-    return out;
+    return new RemoteConfigResult(out, response.getServerEpochTime());
   }
 
   public String getAccountDataReport() throws IOException {

libsignal/service/src/main/java/org/whispersystems/signalservice/internal/push/RemoteConfigResponse.java

@@ -8,10 +8,17 @@ public class RemoteConfigResponse {
   @JsonProperty
   private List<Config> config;
 
+  @JsonProperty
+  private long serverEpochTime;
+
   public List<Config> getConfig() {
     return config;
   }
 
+  public long getServerEpochTime() {
+    return serverEpochTime;
+  }
+
   public static class Config {
     @JsonProperty
     private String name;