Update shortlink to full URL

android_webview/docs/prerelease.md links to the a webview bug filing
template using https://goo.gl/9qkbdn. Since goo.gl is being deprecated,
update this link to the full url.

Test: Open prerelease.md in gitiles and check that the link is the full
Test: url and links to the right place.
Change-Id: I2310e0a962cafde66409e324612de6df80c48ab6
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1635989Reviewed-by: Nate Fischer <ntfschr@chromium.org>
Commit-Queue: Drew Stonebraker <stonebraker@chromium.org>
Cr-Commit-Position: refs/heads/master@{#664453}

android_webview/docs/prerelease.md

@@ -91,7 +91,8 @@ pre-release channels of WebView are not available.
 
 ## Reporting problems with pre-release WebView
 
-Any WebView-related bugs can be filed [here](https://goo.gl/9qkbdn).
+Any WebView-related bugs can be filed
+[here](https://bugs.chromium.org/p/chromium/issues/entry?template=Webview+Bugs).
 
 To best enable us to resolve the issue, please ensure you provide all of the
 information requested in the bug report template.