Fix some annotations on java.util.List.

You can see the source files with the annotations in
https://android-review.googlesource.com/c/platform/libcore/+/700331/1..2
(which obviously is not intended for submission). The .jaif changes
here were copy-and-pasted from the results of running the
extract-annotations tool on those sources. Note that snapshot 1 was
generated from the ojluni.jaif at top of tree, snapshot 2 with these
changes.

Mostly, this is just adding missing @NullFromTypeParam annotations.

The annotations for the parameter to the one-arg toArray were missing
and are added.

The other change is on set(), where the annotation was applied to the
int argument instead of the E argument, which was clearly a mistake.

Test: make docs
Bug: 64930165
Change-Id: I723ad06bbbc05938e69e7fa7a4bebdb4f2a34dcb