libstagefright: Add interlaced video support

Stagefright waits for the Index Settings changed event to be propagated
to it from the component. If interlaced, appropriate flags are given to
the native window.

Change-Id: I240c5139232c6905c3de7632885736147d5f70b1
(cherry picked from commit ce070db0c8d491218adb9a8386116d39909813e9)