[LSC] Remove base::ASCIIToUTF16("...") in //components/autofill

This change removes calls to base::ASCIIToUTF16 in //components/autofill
with a single-line string literal and replaces them with a u"..."
literal instead. Files where this change would cause compilation errors
were not changed.

This is a mechanical change:

$ git grep -lw ASCIIToUTF16 components/autofill | xargs \
    sed -i 's/\(base::\)\?ASCIIToUTF16(\("\(\\.\|[^\\"]\)*"\))/u\2/g'
$ git cl format

Bug: 1189439
Change-Id: I284f7e9233a6fdfc2abb6d66867a084a6fde3588
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2780480
Reviewed-by: Christoph Schwering <schwering@google.com>
Commit-Queue: Jan Wilken Dörrie <jdoerrie@chromium.org>
Owners-Override: Jan Wilken Dörrie <jdoerrie@chromium.org>
Cr-Commit-Position: refs/heads/master@{#865611}