Prevent storing of CCCD's if peer is not bonded.

[h2zero]

Currently a peer that we have paired with but not bonded will have it's
CCCD status stored. We should not store CCCD data unless bonded,
this will prevent that.

#788

[apache-mynewt-bot]

Style check summary

No suggestions at this time!

[rymanluk]

@h2zero thanks for that PR, I see the issue now which is triggered when bonding is actually not used.
imho in such a case we shall not call ble_gatts_bonding_established() this is why there is BLE_HS_DBG_ASSERT(conn->bhc_sec_state.bonded)

I went ahead and did other fix - could you please try that?
#804

[h2zero]

@rymanluk Many ways to skin a cat 😃. #804 is certainly a more correct way that I considered as well, I just didn't have the time and opted for a quick fix. I will close this in favor of yours.