Add more CTS test cases for public APIs of allow rich content in Accessibility Settings.

Enhance security to avoid phishers to trick users or do malicious behavior.

Bug: 149516547
Test: atest AccessibilityServiceInfoTest -c & manual test
Change-Id: Ied1e9ce8fdd36267e456f41458a9808877cc0612
Merged-In: Ied1e9ce8fdd36267e456f41458a9808877cc0612
(cherry picked from commit 7ae9e68d5b41cd56804df88a691b489fadf4e770)
10 files changed