Guard against sample time overflow

Malformed content that has unexpectedly big delta values in stts atom
might cause integer overflow on calculating sample time while preparing
sample table. This commit prevents this situation.

Test: play mp4 file with quite big 'stts' value
Bug: 35985363

Change-Id: I6bc66f77b8b99a14517e56c3ceba9ddb9bf5524d