Use GRANTED_BY_ROLE instead of GRANTED_BY_DEFAULT for system browser.

The two flags are not that different, and other roles are all using
GRANTED_BY_ROLE for system app pregrants, so let's just keep using
GRANTED_BY_ROLE for consistency.

See also b/239498967#comment13 - we provided a platform patch there as a
quick fix, but in the long run I think always using GRANTED_BY_ROLE
makes more sense.

Test: presubmit
Change-Id: I500d9de0f77a98b00a8d237ca09368ef27ca0281
1 file changed