rtla/tests: Add grep checks for base test cases

rtla/tests: Add grep checks for base test cases

Checking for patterns in rtla output with grep was added to test rtla
actions. Add grep checks also for base tests where applicable.

Also fix trace event histogram trigger check to use the correct syntax
for the command-line option so that the test passes with the grep check.

Cc: John Kacur <jkacur@redhat.com>
Cc: Luis Goncalves <lgoncalv@redhat.com>
Cc: Chang Yin <cyin@redhat.com>
Cc: Costa Shulyupin <costa.shul@redhat.com>
Link: https://lore.kernel.org/20250725133817.59237-2-tglozar@redhat.com
Signed-off-by: Tomas Glozar <tglozar@redhat.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>