Increase MAX_HID_DEVICE_COUNT to 10.

As discussed in b/397483126, this value sets the number of BR/EDR HID
devices that can be bonded. This limit of `7` has been reached multiple
times during testing, see b/397483126. Increase the value by ~50% from
`7`->`10`.

Bug: b/397483126 Test: atest BumbleBluetoothTests

Change-Id: I75e8fdfb0c4d2b718ebb2f94a75ea250085f48a6