Put new SQLite APIs behind a flag

The new SQLite APIs are meant for V and so should be guarded by flags
until then.  This change does not disable the APIs, it only flags
them.  Unit tests are not affected.  CTS tests will be disabled in a
subsequent commit.

Bug: 301713419

Change-Id: Icadfa735e997dc7a3d0fbeb7027af43c06943f84
5 files changed