Add a power load test

Bug: 162611167
Test: mp :PowerStatsLoadTests && android shell am instrument -w -e class com.android.frameworks.core.powerstatsloadtests.WiFiLoadTest com.android.frameworks.core.powerstatsloadtests/androidx.test.runner.AndroidJUnitRunner
Test: mp :PowerStatsLoadTests && android shell am instrument -w -e class com.android.frameworks.core.powerstatsloadtests.SystemServiceCallLoadTest com.android.frameworks.core.powerstatsloadtests/androidx.test.runner.AndroidJUnitRunner
Change-Id: Id15e54bf07e558f1e90c788a5b095f8aa37ecbab
7 files changed