libstagefright: httplive: Add NULL check for empty playlist

If the source playlist is empty, the playlist meta will be NULL.
Check for this case to avoid an invalid dereference. Also flag
playlists without the required EXT-X-TARGETDURATION tag as malformed.

CRs-Fixed: 736089
Change-Id: Idf74d890a89bbc6483a6d4060eb092dc7461be24
stagefright: fix for Executing state in resumeLocked

- When resumeLocked is called in Executing state, do
  nothing and return OK to avoid additional state change
  to Executing.

Change-Id: I015ad098d4efd480c1628598f519e96a16537f6e
CRs-Fixed: 740435
libstagefright: Remove parsing deprecated quirk

Remove parsing deprecated quirk "defers-output-buffer-allocation"
in OMXCodec.

Change-Id: Ib9f40f17f927c6af237969ee111bfd74bd63b3fe