libstagefright: Use 64 bit offsets only when needed.

For enabling >2GB recording, 64 bit offsets are
needed for file writing. So, this feature was turned
on by default. This in turn increased the file size.
With this change, by default this feature will be
off and turned on only when required.

- Use 64 bit offsets for resolutions >= 720p.
- Limit maximum file size for recording to 4GB.
- Set max file size only if no value is set from the client
CRs-Fixed: 273144, 285785, 288319, 328461

Change-Id: Ica37cb0414642c68ada18e0b7ba184b55692c6f2