ValueType describes the semantic type of the value that the flag
accepts. Regardless of the ValueType, the Instance.database_flags
field accepts the stringified version of the value, i.e. "20" or
"3.14".
Values:
VALUE_TYPE_UNSPECIFIED (0):
This is an unknown flag type.
STRING (1):
String type flag.
INTEGER (2):
Integer type flag.
FLOAT (3):
Float type flag.
NONE (4):
Denotes that the flag does not accept any
values.
