Use auto specific system property to fix car service package

- With mainline, car service package goes into mainline and package name
  can change depending on who signs it.
- Allow auto product to specify car service package name through
  ro.android.car.carservice.package (=defined in car API surface) so that
  permission allow list can be rely on permissions from the package.
- This should not affect other form factors and auto will add separate
  enforcement for the presence of the package so that this does not bring
  a security risk.

Bug: 221113599
Test: atest android.permission2.cts.PermissionPolicyTest
Change-Id: I5b11fe744b4048dce67b286afd50a18c25d7642a