feat: add notifyUser flag to explicitLeave

app/src/main/java/org/thoughtcrime/securesms/loki/activities/HomeActivity.kt

@@ -358,7 +358,7 @@ class HomeActivity : PassphraseRequiredActionBarActivity, ConversationClickListe
                     isSSKBasedClosedGroup = false
                 }
                 if (isSSKBasedClosedGroup) {
-                    ClosedGroupsProtocolV2.explicitLeave(context, groupPublicKey!!)
+                    ClosedGroupsProtocolV2.explicitLeave(context, groupPublicKey!!, notifyUser = false)
                 } else if (!ClosedGroupsProtocol.leaveLegacyGroup(context, recipient)) {
                     Toast.makeText(context, R.string.activity_home_leaving_group_failed_message, Toast.LENGTH_LONG).show()
                     return@launch

app/src/main/java/org/thoughtcrime/securesms/loki/protocol/ClosedGroupsProtocolV2.kt

@@ -94,8 +94,8 @@ object ClosedGroupsProtocolV2 {
         return deferred.promise
     }
 
-    @JvmStatic
-    fun explicitLeave(context: Context, groupPublicKey: String): Promise<Unit, Exception> {
+    @JvmStatic @JvmOverloads
+    fun explicitLeave(context: Context, groupPublicKey: String, notifyUser: Boolean = true): Promise<Unit, Exception> {
         val deferred = deferred<Unit, Exception>()
         ThreadUtils.queue {
             val userPublicKey = TextSecurePreferences.getLocalNumber(context)!!
@@ -119,7 +119,9 @@ object ClosedGroupsProtocolV2 {
             // Notify the user
             val infoType = GroupContext.Type.QUIT
             val threadID = DatabaseFactory.getThreadDatabase(context).getOrCreateThreadIdFor(Recipient.from(context, Address.fromSerialized(groupID), false))
-            insertOutgoingInfoMessage(context, groupID, infoType, name, updatedMembers, admins, threadID, sentTime)
+            if (notifyUser) {
+                insertOutgoingInfoMessage(context, groupID, infoType, name, updatedMembers, admins, threadID, sentTime)
+            }
             // Remove the group private key and unsubscribe from PNs
             disableLocalGroupAndUnsubscribe(context, apiDB, groupPublicKey, groupDB, groupID, userPublicKey)
             deferred.resolve(Unit)