Fix a number of timestamp mismatches in the mp3 extractor and decoder that...

Fix a number of timestamp mismatches in the mp3 extractor and decoder that would lead to invalid reporting of the current playback time for mono and/or non-44100 kHz mp3s.

Change-Id: I11abc05b62a958ffbc99ca997cd184a2f2199352
related-to-bug: 2667479