Don't reset btif pairing state due to unrelated service discovery

If applications start GATT service discovery just before LE pairing, the discovery conclusion can prematurely reset the pairing state.

Test: mma packages/modules/Bluetooth
Test: Manual | Perform GATT service discovery from phone and initiate pairing from the remote device
Bug: 311790408
Bug: 321996502

Change-Id: I663985bad741c1fd45c9a45ef0af4e52699d96fe