preload: Fix AndroidPrerenderManager::StopPrerendering crash

AndroidPrerenderManager is a global singleton so it may be shared by
multiple tabs, and a mapping is added to the class to fix the problem
accessing a prerender handle which may not exist on the given
WebContents.
https://source.chromium.org/chromium/chromium/src/+/04050bb24084494fa941f38ce218e795b945408b:chrome/browser/ui/android/preloading/java/src/org/chromium/chrome/browser/preloading/AndroidPrerenderManager.java;l=53

Bug: 418730039
Change-Id: I9b6864f06bfcbf6eb03fe29553b53b828291070c
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/6564886
Reviewed-by: Sky Malice <skym@chromium.org>
Commit-Queue: Huanpo Lin <robertlin@chromium.org>
Reviewed-by: Hiroki Nakagawa <nhiroki@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1463229}