geekdroid-firebase: allow to validate QueryPagingSource boundary key
This is useful when ordering by @ServerTimestamp field. When the document
hasn't been sent to server it can't be used as a boundary key has the server
timestamp is null. This change allows client to make the check and avoid an
IllegalArgumentException.
8fcf08607319ae806fac2bbaee65ac6b551739c1 geekttrss-1.5.1
8ba4aeeb83926a175ce3d33b34e40797a3e166c1 geekttrss-1.5.2
8ec7aee97eb67509edde1be6aa39f79c13521e96 geekttrss-1.6.1
784d78097273796d81030144da6c0fda98f570da geekttrss-1.6.2
4bed43bccf240158b266218c136184c21b2887a4 geekttrss-1.6.3
7dfdcb053a3e26f6045042604b4438b2add8f4ad geekttrss-1.6.4
7dfdcb053a3e26f6045042604b4438b2add8f4ad geekttrss-1.6.4
33c9a14b1b6de7aabfd1390a90012e85ba5b4cef geekttrss-1.6.4
1f069f39728964ce6c278618b2ea85aa569c4306 geekttrss-1.6.5
7a8bbdc7b290bc823ed951d6a45aa407fca7e055 geekttrss-1.6.6
f6cf2e8bf04d8e27eb4a77a2a44f327e2ce46957 geekttrss-1.6.7