Fix long click a11y in QSTileViewImpl

The correct label should be used independently of the accessibility
class, as long as the tile is not disabled by policy.

Fixes: 355418825
Test: manual, using Talkback
Test: atest QSTileViewImplTest
Flag: EXEMPT bugfix

Change-Id: Ib7c5c7ccc0b9f8059948bba19304b4261aae8d25