Fixed NPE when local or remote port range does not exist

Added null check for local and remote port range.

Bug: 213523984
Bug: 213139361
Test: atest QosBearerSessionTest
Merged-In: I749f369c0daa5c840a77d37828f65e42262d85f5
Change-Id: I749f369c0daa5c840a77d37828f65e42262d85f5