Convert and store new group changes in MessageExtras.

app/src/main/protowire/Backup.proto

@@ -52,7 +52,7 @@ message AccountData {
     bool linkPreviews = 5;
     bool notDiscoverableByPhoneNumber = 6;
     bool preferContactAvatars = 7;
-    uint32 universalExpireTimer = 8;
+    uint32 universalExpireTimer = 8; // 0 means no universal expire timer.
     repeated string preferredReactionEmoji = 9;
     bool displayBadgesOnProfile = 10;
     bool keepMutedChatsArchived = 11;
@@ -132,7 +132,7 @@ message Chat {
   uint64 recipientId = 2;
   bool archived = 3;
   uint32 pinnedOrder = 4; // 0 = unpinned, otherwise chat is considered pinned and will be displayed in ascending order
-  uint64 expirationTimerMs = 5;
+  uint64 expirationTimerMs = 5; // 0 = no expire timer.
   uint64 muteUntilMs = 6;
   bool markedUnread = 7;
   bool dontNotifyForMentionsIfMuted = 8;
@@ -537,8 +537,10 @@ message SimpleChatUpdate {
   Type type = 1;
 }
 
+// For 1:1 chat updates only.
+// For group thread updates use GroupExpirationTimerUpdate.
 message ExpirationTimerChatUpdate {
-  uint32 expiresInMs = 1;
+  uint32 expiresInMs = 1; // 0 means the expiration timer was disabled
 }
 
 message ProfileChangeChatUpdate {
@@ -591,6 +593,7 @@ message GroupChangeChatUpdate {
       GroupV2MigrationInvitedMembersUpdate groupV2MigrationInvitedMembersUpdate = 31;
       GroupV2MigrationDroppedMembersUpdate groupV2MigrationDroppedMembersUpdate = 32;
       GroupSequenceOfRequestsAndCancelsUpdate groupSequenceOfRequestsAndCancelsUpdate = 33;
+      GroupExpirationTimerUpdate groupExpirationTimerUpdate = 34;
     }
   }
 
@@ -794,6 +797,12 @@ message GroupV2MigrationDroppedMembersUpdate {
   int32 droppedMembersCount = 1;
 }
 
+// For 1:1 timer updates, use ExpirationTimerChatUpdate.
+message GroupExpirationTimerUpdate {
+  uint32 expiresInMs = 1; // 0 means the expiration timer was disabled
+  optional bytes updaterAci = 2;
+}
+
 message StickerPack {
   bytes id = 1;
   bytes key = 2;

app/src/main/protowire/Database.proto

@@ -376,7 +376,10 @@ message ExternalLaunchTransactionState {
 }
 
 message MessageExtras {
-    GV2UpdateDescription gv2UpdateDescription = 1;
+    oneof extra {
+        GV2UpdateDescription gv2UpdateDescription = 1;
+        signalservice.GroupContext gv1Context = 2;
+    }
 }
 
 message GV2UpdateDescription {