Force Widevine to do its own independent check so it goes to Google

[bbondy]

Fix brave/brave-browser#1123

For licensing reasons we need to go to Google for installing Widevine.

Our newer component update server will try to handle any requests for extension updates that gets bundled with other extensions in the same request.
i.e. len(extensions_to_update) == 1 and unrecognized then go to google
server.

The old way this worked was batched with other extnesion update checks at the same time so we would just not return an update from our own server which handled it.

Note that other extensions use the newer component installer which we set as a batch size of 1 so general extension updates are not affected by this.

Submitter Checklist:

• Submitted a ticket for my issue if one did not already exist.
• Used Github auto-closing keywords in the commit message.
• Added/updated tests for this change (for new code or code which already has tests).
• Ran git rebase -i to squash commits (if needed).
• Tagged reviewers and labelled the pull request as needed.
• Request a security/privacy review as needed.
• Add appropriate QA labels (QA/Needed or QA/No-QA-Needed) to include the closed issue in milestone

Test Plan:

Reviewer Checklist:

• New files have MPL-2.0 license header.
• Request a security/privacy review as needed.
• Adequate test coverage exists to prevent regressions
• Verify test plan is specified in PR before merging to source

[emerick]

LGTM

[bbondy]

master: 3f547ff
0.55.x: 5e54185