Recalculate restricted actions each time A11yMenu is opened.

The set of restricted actions may change at runtime, and this also fixes
a testing flake caused by restarting the service multiple times mid
test.

Bug: 347269196
Bug: 357747420
Test: atest AccessibilityMenuServiceTest
Test: Same test on go/abtd
Flag: com.android.systemui.accessibility.accessibilitymenu.hide_restricted_actions
Change-Id: I5517a8a36ceb55f5f4b35d22a1b24ab569cd0426