Generate content description for shortcut label and actions together.

Fix: 373261052
Test: ShortcutHelperCategoriesInteractorTest
Test: ShortcutHelperViewModelTest
Test: Manual. Talkback.
Flag: EXEMPT Bugfix.
Change-Id: I8d6b0e999e8f5a4a890be941240f579c860b7636
9 files changed