Make checkBleState a none blocking call.

BluetoothAdapter.isLeEnabled will at some point call
the Bluetooth service on a non-oneway call.

Try to  post to the main thread to avoid the
Outgoing transactions from this process must be FLAG_ONEWAY
warning.

Flag: EXEMPT bugfix
Bug: 341476279
Test: CTS and make
Change-Id: Icc3012f2b6c554caa3a777ff304216f08de71b0f