Improve logging of ignored setUidMode

If we ignore a setUidMode call that would have changed the op mode,
then:

- Log as an error
- Log the stack trace
- Use the phrase "Blocked setUidMode"

Otherwise:

- Log as a warning
- Don't log the stack trace
- Use the phrase "Ignored setUidMode"

The reason for this is that the former is much more concerning, so we
want to know where it's coming from and to be able to easily search
bugreports for this specific situation.

FLAG: android.permission.flags.runtime_permission_appops_mapping_enabled
Bug: 341219398
Test: presubmit
Change-Id: Ia27838c680ace39adf9221df953fecdf5a40ae1d