Adjust enum to follow protobuf best practices

First value of an enum should contain one of a set list of substrings
that denote a default value.  Included in this list is "UNKNOWN". Change
the order of the values such that the default is first, and rename both
defaults to have "UNKNOWN" for consistency.

Bug: 306760576
Test: m
Change-Id: I595e59c90448c04d26f41da607c2b3342b697139
1 file changed
tree: 08cfd36e40db279b9406fca799614cbb05a1282f
  1. stats/
  2. OWNERS