Set default hidden API policy to dark+black

When invoking dex2oat, only a boolean flag is used to enabled/disable
hidden API checks, instead of a 2-bit value passed down to zygote.
When the flag is true, use dark+black lists as the enforcement policy.
This is conservative, as compiling with both lists enforced may lead
to more classes being re-verified at runtime, but correctness is
preserved.

Bug: 64382372
Bug: 79738462
Test: N/A
Merged-In: If15723ad40b99c5475f10561b5b3a669a8fb01c7
Change-Id: If15723ad40b99c5475f10561b5b3a669a8fb01c7
(cherry picked from commit 46226f02)