Merge "Add AccessibilityAction and AccessibilityEvent API for drag & drop" into sc-v2-dev am: 0e08f81393 am: ff67d5e3e8

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/15585174

Change-Id: I2d9c7f71da5f3ce98d0795d77fed248999d3bc5b