Fix failing VTS test cases

Also, increase number of binder threads in VHAL for performance testing

Fix: b/37543801, b/36778517
Bug: b/36510399

Test: make vts BUILD_GOOGLE_VTS=true -j32 && vts-tradefed run commandAndExit vts --skip-all-system-status-check --primary-abi-only --skip-preconditions --module VtsHalAutomotiveVehicleV2_0Host -l INFO && adb shell /data/nativetest64/android.hardware.automotive.vehicle@2.0-manager-unit-tests/android.hardware.automotive.vehicle@2.0-manager-unit-tests
Change-Id: I850c6be328f1a07ae3fda898a18137c76afe3115