simpleperf: force testing run-as and app_runner separately.

In CtsSimpleperfTestCases, two methods are used to record an app:
through run-as and through simpleperf_app_runner. Tests don't fail
unless both methods fail. This can't detect the situation when only
one method fails. So change to test run-as and simpleperf_app_runner
separately.

Bug: none
Test: run simpleperf_unit_test.

Change-Id: I023aa7793f748e695f809c153ed23f006e13ea12
5 files changed