Optimize AttributionSource tokens - base

For cases where the attribution soruce doesn't need to be
registered as trusted we are now using a shares static
token since the only purpose of the token in these cases
is for watching the source process dying as opposed to that
and security for registered cases.

bug: 192415943

Test: CtsPermissionTestCases
      CtsPermission2TestCases
      CtsPermission3TestCases
      CtsPermission4TestCases
      CtsPermission5TestCases

Change-Id: I93fde9ca1cacada7929761533dcae11b2736ce1e