cancel device discovery before start pairing process

During pairing process, SDP search is needed which cannot be handled
if we are doing device discovery
bug 11294130

Change-Id: Ic025fa3000af4f2d4c2c2ac411d26b6a99ad097c
diff --git a/src/com/android/bluetooth/btservice/AdapterService.java b/src/com/android/bluetooth/btservice/AdapterService.java
index b22cc4f..6c7576a 100755
--- a/src/com/android/bluetooth/btservice/AdapterService.java
+++ b/src/com/android/bluetooth/btservice/AdapterService.java
@@ -1055,6 +1055,10 @@
             return false;
         }
 
+        // Pairing is unreliable while scanning, so cancel discovery
+        // Note, remove this when native stack improves
+        cancelDiscoveryNative();
+
         Message msg = mBondStateMachine.obtainMessage(BondStateMachine.CREATE_BOND);
         msg.obj = device;
         mBondStateMachine.sendMessage(msg);