audioflinger: Fix for Equalizer effect not to turn off

-Equalizer effect is turned off when more than 15 applcations are launched
-Activity manger closing the Equalizer effect when more than 15 application
are launched after music application.
-To resolving this issue removed setEnabled(false) from the AudioFlinger
 disconnect function.

Change-Id: If71a3ccc0be4b8778edcdf30572f026e0bc5f321
CRs-fixed: 376111