Fix incorrect member count during group creation and modification

Resolves issue #13206 where the member count displayed was inaccurate when creating or modifying groups.  The member count now reflects the correct number of participants when selecting/deselecting.

Author: Cale146

app/src/main/java/org/thoughtcrime/securesms/ContactSelectionListFragment.java

@@ -483,7 +483,7 @@ public int getTotalMemberCount() {
       return 0;
     }
 
-    return getSelectedContactsCount() + contactSearchMediator.getFixedContactsSize();
+    return getSelectedMembersSize() + contactSearchMediator.getFixedContactsSize();
   }
 
   private Set<RecipientId> getCurrentSelection() {

app/src/main/java/org/thoughtcrime/securesms/groups/ui/creategroup/CreateGroupActivity.java

@@ -158,12 +158,11 @@ public void onContactDeselected(@NonNull Optional<RecipientId> recipientId, Stri
 
   @Override
   public void onSelectionChanged() {
-    int selectedMembers = contactsFragment.getSelectedMembersSize();
     int selectedContactsCount = contactsFragment.getTotalMemberCount();
     if (selectedContactsCount == 0) {
       getToolbar().setTitle(getString(R.string.CreateGroupActivity__select_members));
     } else {
-      getToolbar().setTitle(getResources().getQuantityString(R.plurals.CreateGroupActivity__d_members, selectedMembers, selectedMembers));
+      getToolbar().setTitle(getResources().getQuantityString(R.plurals.CreateGroupActivity__d_members, selectedContactsCount, selectedContactsCount));
     }
   }