configs: disable split a2dp for msm8909/msm8937/msm8953

Disable split a2dp for msm8909/msm8937/msm8953 by setting
persist.vendor.bt.enable.splita2dp false.

CRs-Fixed: 2212727
Change-Id: Iaaf2114662b3c9d2e0638e62efba9adaf31cb505
3 files changed