stagefright: prefer B frames for high frame-rate recording

Some codecs do not support B-frames with temporal layering.
- Prefer temporal layering for slow-motion and time lapse videos
(since B-frames are not as useful for time lapse, and layering is
 needed for slow-motion)
- Prefer B-frames for HFR capture

Bug: 27596987
Change-Id: I12f530e9f624e2948e176b5548e0d9d65eed95d8