Fix isSystemUi ManagedServiceInfo bool

Checks the status bar permission for ManagedServiceInfos when they're
added, so we can tell which one is SystemUi. Stores value in boolean.
The previous method of doing this, which just checked the caller, won't
work because the caller is usually system server.

Bug: 327471672
Test: build+flash
Flag: ACONFIG android.app.lifetime_extension_refactor STAGING
Change-Id: Ie952cb5d0f1faafb6106b708aa6d18c87b9b3b6c