Disable wtf dropbox entries by default.

Create a list of dropbox tags that are disabled by default. Currently
all tags were enabled by default, so this allows the other way too. We
can then easily turn wtf event collection back on for dogfood.

Bug: 270132337
Test: N/A
Change-Id: Ia678215c34df6ba9a354b3011a90f8f445c493b2
Merged-In: Ia678215c34df6ba9a354b3011a90f8f445c493b2
(cherry picked from commit e70680eb)