VT: ubsan: Prevent assertion by overflowing rtp-time

[JIRA] NEUS7920-21085, SOC-91604
[Problem] signal 6 (SIGABRT), 'ubsan: add-overflow' happened in addNALUnit()
[Cause] RFC3550 doesn't describe value constrains for rtp-time.
        Although it is 4 bytes value by specification,
        it can be even UINT32_MAX and be zero following by UINT32_MAX.
        This overflow derived assertion while calculate the rtp-time.
[Solution] In H264 & H265 assembler,
           modified all time calculation based on int64_t type.
           Now the assemblers recognize overflowed time values sequencially.
           Some values after the overflow, will be treat as "UINT32_MAX + value"

Bug: 175266635

Change-Id: I4a6854ee2063ae7e409650b28e1a9153c441d08d
Signed-off-by: Kim Sungyeon <sy85.kim@samsung.com>