Fix CHIPS for WebView when 3PCs are not enabled

If an Android developer disables 3PCs in their app, paritioned cookies
will not be returned. The root cause of this is that WebView uses its
own settings for cookies from the rest of Chromium.

The behaviour of Chromium is that partitioned cookies are still returned
when 3PCs are disabled so we are matching that.

Because permissions apply at the level of BrowserContext for the rest of
Chromium, we have to do an awkward work around here where we
optimistically retrieve all cookies, and then filter out the non
partitioned cookies. This is because we have no way of telling the lower
layers that this is the behaviour we want for _this_ WebView. There may
be a slight performance impact here but hopefully not a large one since
apps that have 3PCs disabled wouldn't be setting them in the first
place. The real issue is more around apps changing this setting at
runtime.

Bug: 1523962
Change-Id: Ic46a58651d16b85ff9287c52c4f4a89c39274107
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5250507
Commit-Queue: Rupert Wiser <bewise@chromium.org>
Reviewed-by: Maks Orlovich <morlovich@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1257451}