Handling incoming HID connection requests during pairing

Some HID devices request HID connection during pairing or immediately after pairing. Such connection requests get rejected because HID connection policy is set only after pairing and service discovery.
Now such connection requests would not be plumbed to UHID until HID connection policy allows it.

Test: mmm packages/modules/Bluetooth
Test: Manual | Pair with Apple Magic Mouse
Flag: com.android.bluetooth.flags.early_incoming_hid_connection
Bug: 383218863
Bug: 398105207

Change-Id: I527e586ec1c22ce50153381ed849eaea1158798d