Update base::Value list usage in android_webview/

In particular, use Value::List instead of base::Value::ListStorage /
std::vector<base::Value>.

Bug: 1338341
Change-Id: I440ffe07ac302cdfab923ddf54a0b2ff02602233
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/3767157


Commit-Queue: Matt Menke <mmenke@chromium.org>
Reviewed-by: Richard Coles <torne@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1026908}