Support talkback for functions on the caption view.

Accessibility talkback feature works partially.
Support talkback for a title on caption view.

Test: manual
1. Enable Accessibility TalkBack
2. Execute application with freeform
3. Touch title on the freeform window
4. Check speech "App in Pop-up window"

Bug: 144271785

Change-Id: I5ab3cd23610f37a8b930de4710abf8ae62f65b84
(cherry picked from commit b51a68057f5d1498e3a87a10928d8377ad82acd0)