Media Player fix for pause after system suspend/resume

Description: During system wide suspend/resume call, the state machine for
stagefright player & awesome player are reset and the flags are updated
accordingly. But the state variables inside Media player class are left
at the play/paused state depending on the current state while suspend call
is issued.
because of this mismatch in the states between media player and the awesome
player, the subsequent calls to isPlaying() query inside media player is
setting the state to Paused as a error correction mechanism. since the
media player state is incorrectly set as paused, even though it was in started
state during suspend, all the subsequent calls to pause will return without
any action.

Inorder to correct this, the suspend state is introduced in the media player.
The current state is saved during suspend and is properly restored on resume
call.

Validation: Tested AV playback pause/resume several times along with multiple
system wide suspend/resume transitions.

Change-Id: If7d40260c05899fac551edabaa8051bac1d0d020
Signed-off-by: Sunita Nadampalli <sunitan@ti.com>