[Android] Get plus address IPH string directly from the resources.

Before this CL, the plus address IPH text was passed in the
Suggestion object from C++ to Java. Plus addresses strings were moved
to an internal repo. This made it possible to obtain plus address
strings directly from the resources.

Bug: 346469807
Change-Id: Icb9e60bed01f0e81923400fdc3b6d053e48b3b15
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/6256856
Reviewed-by: Friedrich Hauser <friedrichh@chromium.org>
Commit-Queue: Timofey Chudakov <tchudakov@google.com>
Cr-Commit-Position: refs/heads/main@{#1419189}