Remove BLE_DELAY_REQUEST_ENC

If it is enabled, the logic makes no sense.

The security flags are stored in 2 bytes.
The upper byte is LE security flags, and the lower byte is classic flags.
It is checking the classic flags to determine whether to start
BLE encryption.

It was false by default.

Bug: 159815595
Tag: #refactor
Test: compile & verify basic functions working
Change-Id: Ifabf514e20c2bc95d2f81a94158b8b63c5e2db6d