LE Audio: Return SDP services if GATT discovery on LE transport fails

Right now, if GATT discovery fails, we would prevent any services from
being connected in Settings on dual mode device.

After this patch, if LE GATT discovery fails, we will fall back to
SDP only services, which should keep the audio devices usable.

Bug: 278804760
Test: pair with LE Audio capable device that would fail to establish LE
connection, or time out during GATT service discovery
(cherry picked from https://android-review.googlesource.com/q/commit:4d5d871ab40ab59e25332be14e8d7187a7f95450)
Merged-In: I734f792cb841d44e04748fd421fbfe458bb4ff41
Change-Id: I734f792cb841d44e04748fd421fbfe458bb4ff41