Sanitize a11y qs shortcut tile service name before using it

Get the valid a11y tile services outside of the lock mechanism to
prevent AccessibilityManagerService holding the lock for a long time
while processing valid tile services by calling PackageManager

Bug: 449392803
Bug: 441506794
Test: manual
Test: atest AccessibilityUserStateTest
Test: atest AccessibilityTileUtilsTest
Test: atest AccessibilityManagerServiceTest
Flag: EXEMPT CVE_FIX

Cherrypick-From: https://googleplex-android-review.googlesource.com/q/commit:637f5b4aa4fbc87010f49f69555f6d14caef6a1f
Cherrypick-From: https://googleplex-android-review.googlesource.com/q/commit:25fdbe5f215f24201f4c2e526cbfa801f6f1d10b
Merged-In: Id05b4fe4ee0619d2bdc0421e8bfc5b4d62e322e0
Change-Id: Id05b4fe4ee0619d2bdc0421e8bfc5b4d62e322e0