csis: Allow to connect profile only when device is bonded

Fixing a race, when profile Connect message reach the native stack just
after device got unbonded.

Bug: 329781005
Test: atest bluetooth_csis_test
Flag: Exempt, Fixing race which will happen only on the stress tests
Change-Id: Iec2b5dd78fe11c1705d50f3f92d29686e45dfaac