Added global retry support

The retry timer suggested by the network will persist
accross network requests. Also changed the retry timer
to a 64-bit value to be consistent with types used in
Android time APIs.

(clean cherry-pick)

Test: FrameworksTelephonytests
Fix: 159672248
Merged-In: Ifc44f3265492c7862d7daa97c1141e1f6eefc0b3
Change-Id: Ifc44f3265492c7862d7daa97c1141e1f6eefc0b3