Allow m.google.com resumable upload URLs in FileUploadDelegate

By default, BrowserPolicyConnector::GetFileStorageServerUploadUrl()
constructs the file storage upload URL from the DMServer URL
(https://m.google.com/devicemanagement/data/api/upload). However,
IsUrlAllowed() in file_upload_impl.cc only allowed googleapis.com,
causing log uploads to fail in DoNextStep() and DoFinalize() with
"Corrupt resumable upload URL".

Allow m.google.com in addition to googleapis.com in IsUrlAllowed().
Update FileUploadDelegateTest to use https://m.google.com URLs and
rewrite forwarded request URLs in InterceptingURLLoaderFactory to target
the local EmbeddedTestServer, removing the need for the 127.0.0.1 /
localhost test bypass in IsUrlAllowed().

Bug: 559107661
Change-Id: I553e4697b77f236519c4fc17e2e76a414a7fe63d
Tests: Updated unit tests
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/8500851
Reviewed-by: Shanthanu Bhardwaj <xanth@google.com>
Commit-Queue: Shanthanu Bhardwaj <xanth@google.com>
Cr-Commit-Position: refs/heads/main@{#1711105}