Stops hiding a11y services with the same package+label as an activity.

Bug: 353700779
Test: atest AccessibilitySettings, ensure new test passes
Test: revert AccessibilitySettings.java change, ensure new test fails
Test: Install poc APKs from the bug, observe issue not reproducible
Flag: NONE security fix
(cherry picked from https://googleplex-android-review.googlesource.com/q/commit:c38fd822ba27224c179b80de2b89a1e9ab8bee59)
(cherry picked from https://googleplex-android-review.googlesource.com/q/commit:ccc0d9d0ebace1cf0925b7c696bc41d6cf9efe52)
Merged-In: Ie680e80169aa734f2559fe50ef06e4d1eae46779
Change-Id: Ie680e80169aa734f2559fe50ef06e4d1eae46779