Android: Run TraceReferences on base+chrome when validating bundles

We already ran it on all dex, and on base only. This adds base+dex in
order to check that chrome module doesn't reference code defined in
feature splits.

Also fixes our "Tip: Build with:" error prefix not being added due
to the output of TraceReferences changing at some point.

Bug: 1313462
Change-Id: Ia7e7dee0a80a9600022c959858b5c459269a59dc
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/3572866
Reviewed-by: Sam Maier <smaier@chromium.org>
Commit-Queue: Andrew Grieve <agrieve@chromium.org>
Cr-Commit-Position: refs/heads/main@{#989742}