Add tracing for ContentProviders.

You could squint at raw Binder transactions to try detecting calls
like these, but there are several ContentProviders inside the OS
that either call into themselves, or call into providers within the
same process, which means it's more difficult to triage slow calls
without explicit visibility.

Bug: 112080089
Test: manual
Change-Id: I4e1e026f2bdc43d179c796d892e84af6da559f3a