Fixed WFC activation issue

When CBS APN is used, both DNN and OsAppId are filled
in the traffic descriptor. Making the logic change so that
when DNN is filled, matchAllRulesAllowed flag will be set
to true so that if the specified slice does not exist, the
default slice could be used to setup the PDN.

Test: Manual + atest DataNetworkTest
Fix: 222333150
Change-Id: Idfb232952a84e892937352ea183639d78aa61020
Merged-In: Idfb232952a84e892937352ea183639d78aa61020