stagefright: rtsp: handle overflow in jitter calculation

Handle scenario when base jitter is fully 32-bit long.

Bug: 301990510
Test: Video long call / VT generic test
(cherry picked from https://googleplex-android-review.googlesource.com/q/commit:d20718719936096c81b9681c54c501e4bd31408e)
Merged-In: Ic0a4807885429da5354f0b3fc83c6198a20d9c44
Change-Id: Ic0a4807885429da5354f0b3fc83c6198a20d9c44