Fixing the announcement of menu of a11y actions when using Talkback

or Switch Access.

Root cause:
The accessibility delegate was used for the root view instead of items.

Actions:
1) Add the accessibility delegate to the individual items
of the RecyclerView, and then override the functions
onInitializeAccessibilityNodeInfo() and performAccessibilityAction().

2) Remove the overridden functions onInitializeAccessibilityNodeInfo()
and performAccessibilityAction() from the root view.

Bug: 190326499
Bug: 190138534
Test: manual test
Change-Id: Ife1787c2d7bb3090e4d55aed76c303e9842a1a98