Display message when hearing aid has no presets configured. Previously, the preset item was grayed out with no explanation, causing confusion. Now, a clear message informs users that presets are not available on their device.
Bug: 345112286
Test: atest BluetoothDetailsHearingAidsPresetsControllerTest
Flag: EXEMPT bugfix
Change-Id: Ie1ece8f08933eb28a5947e2a030888a6bc49bc9f