Rename wlist to allowlist

The new release of re-client renames env_var_wlist to env_var_allowlist.
We need to make this change as part of the topic so that with the new
release we are able to deprecate this variable.

Bug: b/167677318
Change-Id: I988381f4f72061f7c6eb99d58593f92cfd618b1b
Merged-In: I988381f4f72061f7c6eb99d58593f92cfd618b1b