This adds support for the "regex" flag for both the "whitelist" and
"blacklist" conditional types. Before, only the "any_one_of" and
"not_any_of" conditionals supported this. Similar to the pre-existing
regex logic, the patterns are matched from the beginning of the string,
meaning you may need prefix them with ".*" if you do not care about the
first characters of the match.
Closes-Bug: #1880252
Change-Id: Ia51f47a58712c7230753f2cfa0c87b83a7339bf9
feaf034438