Always send BTA_DM_GATT_OVER_LE_RES_EVT

If doing gatt discovery, we should always send this event to the upper
layer on its conclusion. Otherwise we get the pairing_cb stuck.

Bug: 263050668
Test: manual
(cherry picked from https://android-review.googlesource.com/q/commit:3380f3ddf0dedc8d0cb3ca7256711bff5c2aee98)
Merged-In: I65aa5cddc3fe5a9f5c8b9e2d43d676bf3d9082b7
Change-Id: I07621dd098ad887c82927a3af9f41ac2b31c15b0