This commit fixes an oversight in LabelTypeSerializer. While there was a
test to check for canOverride, the test just used the default value and
hence didn't actually test the behavior. At the same time, we forgot to
(de)serialized the value. This commit fixes that and uses inverted defaults
in the test wherever there are explicit booleans use in Builders.
Since this value is part of the ProjectCache, we increase the cache version
to disregard previously serialized values.
Change-Id: I83507c9426d7cd708b5ceef15648e5fddbd805f7
5e851d06d2