media: Add new API to set next output file.

Only support recording to MP4 file now. When the recorded file is approcaching
file size limit, application will receive
MEDIA_RECORDER_INFO_MAX_FILESIZE_APPROACHING callback from mediarecorder.
Application could use setNextOutputFile to set the next output file before or
after receiving this callback. Upon reaching filesize limit, recorder will swap
the output file internally and notify application with
MEDIA_RECORDER_INFO_NEXT_OUTPUT_FILE_STARTED.

Test: Hack camera app to record more than filesize limit.
Bug: 28150626
Change-Id: I2daf8f798fe3631d6b7ef48ebea3a64ab4566f2d