Add group terminate support.

app/src/main/java/org/thoughtcrime/securesms/util/CommunicationActions.java

@@ -286,8 +286,8 @@ public class CommunicationActions {
     SimpleTask.run(SignalExecutors.BOUNDED, () -> {
       GroupRecord group = SignalDatabase.groups().getGroup(groupId).orElse(null);
 
-      return group != null && group.isActive() ? Recipient.resolved(group.getRecipientId())
-                                               : null;
+      return group != null && (group.isMember() || group.isTerminated()) ? Recipient.resolved(group.getRecipientId())
+                                                                         : null;
     },
     recipient -> {
       if (recipient != null) {

app/src/main/java/org/thoughtcrime/securesms/util/RemoteConfig.kt

@@ -1303,5 +1303,17 @@ object RemoteConfig {
     defaultValue = 0,
     hotSwappable = true
   )
+
+  /**
+   * Whether or not to allow admins to terminate groups.
+   */
+  @JvmStatic
+  @get:JvmName("groupTerminateSend")
+  val groupTerminateSend: Boolean by remoteBoolean(
+    key = "android.groupTerminateSend",
+    defaultValue = false,
+    hotSwappable = true
+  )
+
   // endregion
 }