Revert "libmedia: Add flag for non-native FAST tracks."

 * Changing design of this, no longer needed.

This reverts commit a667d25f10063679829f3eca39d6d6d84d3ac05e.

Change-Id: If8e348cdf53f01314a05fa4ea1a5dfdec6cc24ba
Merge "Revert "libmedia: Add flag for non-native FAST tracks."" into kitkat