logd: test: check sepolicy background rate before testing

logd.sepolicy_rate_limiter_* tests can fail individually so join them
together into one test.  The new test logd.sepolicy_rate_limiter
fails as a group if the background sepolicy activity is too high, so
check it and report a warning that the test can fail as a result so it
can be forgiven during unit testing.  The failure remains as a VTS
performance threshold that requires investigation.

The test takes a total of 45 seconds to run, it was split up as this
approaches the 60 second test timeout on go/apct.

Test: gTest logd-unit-tests --gtest_filter=logd.sepolicy_rate_limiter
      (run in loop ensuring passes do not interfere with eachother)
Bug: 37791296
Change-Id: Ia865241f684c6b0de428702cbd5110dc17927c66
1 file changed