Handle new zygote flags in ART

Add support for DISABLE_VERIFIER and ONLY_USE_SYSTEM_OAT_FILES.

bug: 30972906
bug: 63920015

Test: device boots
Change-Id: I7c4eddc070908aed980d54d374c0b261d1f32d57
diff --git a/runtime/runtime.cc b/runtime/runtime.cc
index 5888762..c68c341 100644
--- a/runtime/runtime.cc
+++ b/runtime/runtime.cc
@@ -2330,6 +2330,10 @@
   }
 }
 
+void Runtime::DisableVerifier() {
+  verify_ = verifier::VerifyMode::kNone;
+}
+
 bool Runtime::IsVerificationEnabled() const {
   return verify_ == verifier::VerifyMode::kEnable ||
       verify_ == verifier::VerifyMode::kSoftFail;