Make performAccessibilityShortcut a SystemAPI

Also create a new MANAGE_ACCESSIBILITY permission to
perform the shortcut.

Bug: 116118615
Test: make, activate accessibility shortcut
Change-Id: Ic65a0cdf7393429e14cb98f4fb0734d20069b05a
diff --git a/data/etc/privapp-permissions-platform.xml b/data/etc/privapp-permissions-platform.xml
index 28e92db..8964ee3 100644
--- a/data/etc/privapp-permissions-platform.xml
+++ b/data/etc/privapp-permissions-platform.xml
@@ -313,6 +313,7 @@
         <permission name="android.permission.INSTALL_PACKAGES"/>
         <permission name="android.permission.INTERACT_ACROSS_USERS"/>
         <permission name="android.permission.LOCAL_MAC_ADDRESS"/>
+        <permission name="android.permission.MANAGE_ACCESSIBILITY"/>
         <permission name="android.permission.MANAGE_ACTIVITY_STACKS"/>
         <permission name="android.permission.MANAGE_DEVICE_ADMINS"/>
         <permission name="android.permission.MANAGE_USB"/>