Hide mistakenly exposed system typedef annotations

Typedef annotations are not meant to be in the SDK, so hide them with
@removed, which keeps the record that they were exposed previously.

Note that some of these are added to removed.txt rather than
system-removed.txt. I think this is a limitation of @removed that I'm
not quite sure how to address (other than adding it to the @removed
comment).

Bug: 309971481
Test: m checkapi
Change-Id: Ib1ea01edf193c5fae6729784769b98407f1dc945