lisa: Rename dataframe columns to match new util est events
Rename util est event names fields to match the new format:
CPU runqueue event: -0 [006] 31.821200: sched_util_est_cfs: cpu=6 path=/ enqueued=5 ewma=0 util=526
Task event: -0 [006] 31.821202: sched_util_est_se: cpu=6 path=(null) comm=rcu_preempt pid=10 enqueued=4 ewma=5 util=2