Added support for unbounded ranges to ODIDUtil.get_dtcp_aligned_end()

The function wasn't handling the case where the range end was unbounded.
 Now it's capped to int64.MAX instead of overflowing.

Tested with DTCP-protected in-progress recording content that was
 previously failing.
Merge branch 'cablelabs/master' into cbl_cpratt/mp4-time-seek.seg