Allow existing HID pending connections to continue.

Currently, BT_STATUS_BUSY will be sent back to JNI when a new connection request comes from the same remote device, and end the connection instead of waiting for the previous connection attempt to finish.

Tag: #stability
Bug: 174127136
Test: manual through repeated connections in ADT3 OOBE
Change-Id: I714c7a1b01b2d5e9235a1404711f795f3136fc68