simpleperf: fix tests in cloud android.

simpleperf: fix tests in cloud android.

Cloud android uses x86 cuttlefish without hardware counters and
tracepoint events.
Fix simpleperf tests before adding them to presubmit check:
 1. In HasHardwareCounter(), mark cf_x86 platform as not having
hardware counters. So tests needing hardware counters will be
skipped on cloud android.
 2. Modify most record_cmd tests to not requiring hardware
counters, and use task-clock instead of cpu-cycles when hardware
counters are not available.
 3. Skip tests needing tracepoint events on cloud android.

Bug: none
Test: run simpleperf_unit_tests on cuttlefish.
Change-Id: Id776b86a1248d4ac80ae96e308520f3a41a54184