binder: Add std::vector<bool> specialization to SafeInterface

Adding this to support migration and enhancement of
IGraphicBufferProducers and IGraphicBufferConsumers.

We'd ideally use AIDL, but we can't migrate until all the users of these
raw binder classes are no longer using them.

Bug: n/a
Flag: EXEMPT new unused function
Test: new test
Change-Id: I11288f4823751343c7f5e158cfda88aad66ea5dc